Disclosed is a method of producing a multilayer printed-wiring board containing at least a metal plate (1) as an inner layer plate. The method comprises the steps of: forming as the metal plate a metal plate having a peripheral portion (3) which is a non-product portion, and a product portion (2) surrounded by the non-product portion, the peripheral portion (3) and the product portion (2) being partially connected; filling an insulating material (10) in non-­connecting portions (16) formed between the peripheral portion and the product portion; laminating the metal plate (1) with another inner layer plates to form a multilayer body (20); and separating the peripheral portion from the product portion within the regions (16) in which the insulating material (10) is filled.