A semiconductor part 1 in which a metal terminal 2 is formed on its back surface and side surface is mounted so that only the back surface portion of the metal terminal 2 is in contact with a cream solder 3. When the side surface portion of the metal terminal 2 is irradiated with laser beams, the back surface portion of the metal terminal 2 is heated by thermal conduction from the side surface portion to the back surface portion of the metal terminal 2 and the cream solder 3 in contact with the back surface portion of the metal terminal 2 is melted, whereby soldering is performed.