Disclosed is a method for bending a metal plate comprising: a first forming step (A) for obtaining a first formed member having a bent portion; and a second forming step (B) for bending the first formed member in a direction of a bending direction of the bent portion so as to allow the bent portion of the first formed member to receive bending-back force. In bending a metal plate by a forming punch relatively moving to a forming die side, the metal plate is bent in an arch shape round the bent forming portion of the forming die. The angle nullp formed between an inclined flat forming portion and a horizontal flat forming portion of the forming die is set to nullp>0, so that the bent arch portion abuts with the inclined flat forming portion of the forming punch and the inclined flat portion of the forming die simultaneously for a certain period of time. This reduces the angle change defect of the bent portion of the formed portion, with no need of changing product shape or of preparing for a special forming die or a facility.