Its wordings
Arbitration Act
Article 23, paragraph (1)
第二十三条第一項
Each amendment that changed this provision, and each that will, oldest first. Each is shown against the wording just before it; where an amendment gives the provision another number, it is followed under the new one. Read it as it stands today
In force today
An arbitral tribunal may rule on its own jurisdiction (meaning the authority to carry out proceedings in an arbitration procedure and to make an arbitral award; hereinafter the same applies in this Article), including a ruling on any allegations on the existence or validity of an arbitration agreement.
仲裁廷は、仲裁合意の存否又は効力に関する主張についての判断その他自己の仲裁権限（仲裁手続における審理及び仲裁判断を行う権限をいう。以下この条において同じ。）の有無についての判断を示すことができる。