To provide a composite material member for semiconductor device, an insulated semiconductor device and non-insulated semiconductor device using the composite material member, which are effective for obtaining a semiconductor device that alleviates thermal stress or thermal strain occurring during production or operation, has no possibilities of deformation, degeneration and rupture of each member, and is highly reliably and inexpensive. The composite material member for semiconductor device is characterized by being a composite metal plate with particles composed of cuprous oxide dispersed in a copper matrix, in which a surface of the composite metal plate is covered with a metal layer, and a copper layer with thickness of 0.5 &mgr;m or larger exists in an interface formed by the composite metal plate and the metal layer.