Abstract: A thermosetting double-sided adhesive insulating resin is disposed on a ceramic plate. A metal plate is disposed on the thermosetting double-sided adhesive insulating resin and bonded to an upper surface of the ceramic plate via the thermosetting double-sided adhesive insulating resin. The thermosetting double-sided adhesive insulating resin is low cost and free from problems with an aspect of member supply as well. Since the thermosetting double-sided adhesive insulating resin eliminates a divergence in coefficients of linear expansion between the ceramic plate and the metal plate, it is possible to prevent cracking of the ceramic plate during heating and peeling of the metal plate from the ceramic plate. Since the thermosetting double-sided adhesive insulating resin can maintain adhesiveness, it is possible to prevent the generation of voids, thereby improving product reliability.