If the contractor delivers to the party ordering work of a content the subject matter of work that does not conform to the contract terms with respect to the kind or quality (in the case of the subject matter of work that is not required to be delivered, if the subject matter of work does not conform to the terms of the contract with respect to the kind or quality when the work is finished), the party ordering work may not demand completion of the non-conformity of performance, demand a reduction of the remuneration, claim damages, or cancel the contract, on the grounds of the non-conformity caused by the nature of the materials that the party ordering work has provided or any instructions that the relevant party has given; provided, however, that this does not apply if the contractor knew that the materials or instructions were inappropriate but did not notify the ordering party of this.
請負人が種類又は品質に関して契約の内容に適合しない仕事の目的物を注文者に引き渡したとき（その引渡しを要しない場合にあっては、仕事が終了した時に仕事の目的物が種類又は品質に関して契約の内容に適合しないとき）は、注文者は、注文者の供した材料の性質又は注文者の与えた指図によって生じた不適合を理由として、履行の追完の請求、報酬の減額の請求、損害賠償の請求及び契約の解除をすることができない。ただし、請負人がその材料又は指図が不適当であることを知りながら告げなかったときは、この限りでない。