# 民事訴訟法 / Code of Civil Procedure — 第四十条 (Article 40) - Law: 民事訴訟法 (Code of Civil Procedure), 平成八年法律第百九号 - English title "Code of Civil Procedure": Ministry of Justice translation - Kind: Act — the distinction between 法律 (Act), 政令 (Cabinet Order), 省令 (Ministerial Order) and 条例 (local ordinance) decides who may issue it and what it may say. - Provision: 第四十条 (Article 40)（必要的共同訴訟） — address `art-40` - Text in force since: 2026-06-24 - URL (the page that opens at this provision): https://japanlaw.org/en/code-of-civil-procedure/art-40 - Permanent URL (e-Gov law ID, never renamed): https://japanlaw.org/l/408AC0000000109/art-40 - Every provision below carries its address and both URLs on the line under it. - Japanese text: e-Gov 法令検索, Digital Agency (デジタル庁). English: as marked on each line below. Only the Japanese as published by the government has legal effect; the text below is a copy of it. Every English rendering below is a translation and says which kind: the Ministry of Justice's translation, or this site's machine translation, whose model and date the Sources list names. They are never merged and never substituted for one another. --- ### 第四十条（必要的共同訴訟） — (Mandatory Joint Litigation) caption: Ministry of Justice translation — Japanese Law Translation Database System art-40 · https://japanlaw.org/en/code-of-civil-procedure/art-40 · https://japanlaw.org/l/408AC0000000109/art-40 **第一項** 訴訟の目的が共同訴訟人の全員について合一にのみ確定すべき場合には、その一人の訴訟行為は、全員の利益においてのみその効力を生ずる。 art-40/par-1 · https://japanlaw.org/en/code-of-civil-procedure/art-40/par-1 · https://japanlaw.org/l/408AC0000000109/art-40/par-1 If the subject matter of litigation is to be determined for all co-litigants only as a unified matter, procedural acts performed by one of them become valid only in the interests of all of the co-litigants. Ministry of Justice translation — Japanese Law Translation Database System **第二項** 前項に規定する場合には、共同訴訟人の一人に対する相手方の訴訟行為は、全員に対してその効力を生ずる。 art-40/par-2 · https://japanlaw.org/en/code-of-civil-procedure/art-40/par-2 · https://japanlaw.org/l/408AC0000000109/art-40/par-2 In a case prescribed in the preceding paragraph, procedural acts performed against one of the co-litigants by the adverse party are valid against all of them. Ministry of Justice translation — Japanese Law Translation Database System **第三項** 第一項に規定する場合において、共同訴訟人の一人について訴訟手続の中断又は中止の原因があるときは、その中断又は中止は、全員についてその効力を生ずる。 art-40/par-3 · https://japanlaw.org/en/code-of-civil-procedure/art-40/par-3 · https://japanlaw.org/l/408AC0000000109/art-40/par-3 In a case prescribed in paragraph (1), if there are grounds for a continuance or suspension of litigation proceedings with regard to one of the co-litigants, the continuance or suspension is valid against all of them. Ministry of Justice translation — Japanese Law Translation Database System **第四項** 第三十二条第一項の規定は、第一項に規定する場合において、共同訴訟人の一人が提起した上訴について他の共同訴訟人である被保佐人若しくは被補助人又は他の共同訴訟人の後見人その他の法定代理人のすべき訴訟行為について準用する。 art-40/par-4 · https://japanlaw.org/en/code-of-civil-procedure/art-40/par-4 · https://japanlaw.org/l/408AC0000000109/art-40/par-4 The provisions of Article 32, paragraph (1) apply mutatis mutandis, in the case prescribed in paragraph (1), to procedural acts that a co-litigant who is a person under curatorship or person under assistantship, or a guardian or other legal representative is required to perform in an appeal filed by one of the co-litigants. Ministry of Justice translation — Japanese Law Translation Database System --- ## Cites - art-40/par-2: 前項 → 民事訴訟法 第四十条第一項 (Article 40, paragraph (1)), art-40/par-1 — https://japanlaw.org/en/code-of-civil-procedure/art-40/par-1 · https://japanlaw.org/l/408AC0000000109/art-40/par-1 - art-40/par-3: 第一項 → 民事訴訟法 第四十条第一項 (Article 40, paragraph (1)), art-40/par-1 — https://japanlaw.org/en/code-of-civil-procedure/art-40/par-1 · https://japanlaw.org/l/408AC0000000109/art-40/par-1 - art-40/par-4: 第三十二条第一項 → 民事訴訟法 第三十二条第一項 (Article 32, paragraph (1)), art-32/par-1 — https://japanlaw.org/en/code-of-civil-procedure/art-32/par-1 · https://japanlaw.org/l/408AC0000000109/art-32/par-1 - art-40/par-4: 第一項 → 民事訴訟法 第四十条第一項 (Article 40, paragraph (1)), art-40/par-1 — https://japanlaw.org/en/code-of-civil-procedure/art-40/par-1 · https://japanlaw.org/l/408AC0000000109/art-40/par-1 ## Cited by 7 provisions cite this one. No official source publishes this direction. - 民事訴訟法 第三十二条第一項（被保佐人、被補助人及び法定代理人の訴訟行為の特則） — https://japanlaw.org/en/code-of-civil-procedure/art-32/par-1 · https://japanlaw.org/l/408AC0000000109/art-32/par-1 - 民事訴訟法 第四十条第二項（必要的共同訴訟） — https://japanlaw.org/en/code-of-civil-procedure/art-40/par-2 · https://japanlaw.org/l/408AC0000000109/art-40/par-2 - 民事訴訟法 第四十条第三項（必要的共同訴訟） — https://japanlaw.org/en/code-of-civil-procedure/art-40/par-3 · https://japanlaw.org/l/408AC0000000109/art-40/par-3 - 民事訴訟法 第四十条第四項（必要的共同訴訟） — https://japanlaw.org/en/code-of-civil-procedure/art-40/par-4 · https://japanlaw.org/l/408AC0000000109/art-40/par-4 - 民事訴訟法 第四十七条第四項（独立当事者参加） — https://japanlaw.org/en/code-of-civil-procedure/art-47/par-4 · https://japanlaw.org/l/408AC0000000109/art-47/par-4 - 破産法 第百二十六条第六項（破産債権査定申立てについての決定に対する異議の訴え） — https://japanlaw.org/en/bankruptcy-act/art-126/par-6 · https://japanlaw.org/l/416AC0000000075/art-126/par-6 - 行政事件訴訟法 第二十二条第四項（第三者の訴訟参加） — https://japanlaw.org/en/administrative-case-litigation-act/art-22/par-4 · https://japanlaw.org/l/337AC0000000139/art-22/par-4 --- ## Sources - e-Gov 法令検索, Digital Agency (デジタル庁) — 民事訴訟法 — the text in force from 2026-06-24 (https://laws.e-gov.go.jp/law/408AC0000000109/20260624_508AC0000000046), retrieved 2026-10-17 - Japanese Law Translation Database System, Ministry of Justice (法務省) — Code of Civil Procedure — Ministry of Justice translation (https://www.japaneselawtranslation.go.jp/en/laws/view/4797/tb), retrieved 2026-10-17 - This site's parser, version 209 — 民事訴訟法 — structure, counts, cross-references and defined terms, computed 2026-10-17