A member for a semiconductor apparatus for carrying or holding a semiconductor device, obtained by joining an aluminum nitride substrate and a radiating substrate, comprises an insulating member formed by an aluminum nitride sintered body to be provided thereon with the semiconductor device, a radiating member to be joined to the insulating member, which radiating member is mainly formed of a copper-tungsten alloy or a copper-molybdenum alloy, a stress relieving member interposed between the insulating member and the radiating member and a silver solder member for joining the insulating member, the stress relieving member and the radiating member with each other. The stress relieving member is prepared by copper or a copper alloy, implementing a soft metal or a soft alloy having high plastic deformability, in order to relax, by its own plastic deformation, thermal stress caused by difference in thermal expansion coefficient between the insulating member and the radiating member in a cooling step upon soldering.