A semiconductor device includes: a semiconductor chip having an electrode on one surface; a first conductive member disposed on one surface side of the semiconductor chip; a metal member having a base member and a membrane and disposed between the semiconductor chip and the first conductive member; a first solder disposed between the electrode of the semiconductor chip and the metal member; and a second solder disposed between the metal member and the first conductive member. The membrane has a metal thin film arranged on the surface of the base member and an uneven oxide film. The uneven oxide film is arranged on the metal thin film in at least a part of a connection region of a surface of the metal member, the connection region connecting a first connection region to which the first solder is connected and a second connection region to which the second solder is connected.