PURPOSE: To improve the heat radiating characteristic by a method wherein a metallic plate is provided on the plane different from the plane wherein the lead between leads is provided.

CONSTITUTION: The lead terminal which is wire-bonded to a pad on an IC chip is constituted on the A plane 22. A supporting wire 24 is the part except for the lead terminal contained in a plastic, which fixes the frame part sunk into the B plane 23 and stabilizes it. The supporting wire 24 is removed together with the frame for fixing lead terminals after plastic molding. The problem in board mounting does not occur, except that the cross section of the supporting wire to stabilize the internal frame in the B plane 23 between lead terminals at the time of assembly is partially exposed.