To provide a semiconductor device operable at a temperature higher than a bonding temperature of a semiconductor element and a mounting member; and provide a manufacturing method of the semiconductor device and provide a mounting member.

A semiconductor device comprises a substrate 70, a frame part 36 and a semiconductor element 20. The substrate 70 is composed of metal containing copper. The frame part 36 includes a first insulation material 32 and a conductive part 33. A joint metal layer 51 is provided in a region which is surrounded by the frame part 36 on a surface of the substrate 70 and which contains copper. The semiconductor element 20 is provided on the joint metal layer 51. The joint metal 51 includes first metal which is either of copper or copper alloy, second metal which is dispersed in the first metal and which is any one of tin, zinc and indium, and third metal which is dispersed in the first metal and which is either of gold or platinum. A solid solution layer 49 in which a percentage of the first metal is higher than a percentage of the second metal and the percentage of the second metal is higher than a percentage of the third metal joins the semiconductor metal 20 and the substrate 70.