PRINTED WIRING BOARD

A printed wiring board according to an embodiment includes a metal plate and a wiring member. The meal plate includes a current path part, which is a main current path of an electronic part mounted on or above a front surface of the metal plate, and a heat radiation part, which radiates heat generated from the electronic part. The wiring member is arranged on or above a back surface of the metal plate. The current path part and the heat radiation part are in the same layer to be integrally formed with the wiring member.