In a package wherein a lead part coupled to a semiconductor element by wire bonding, an element retention member to retain the semiconductor element on the top face side and radiate heat on the bottom face side, and an insulative partition part to partition the lead part from the element retention member with an insulative resin appear, a creeping route ranging from the top face to retain the semiconductor element to a package bottom face on a boundary plane between the element retention member and an insulative partition part includes a bent route having a plurality of turns. Consequently, it is possible to inhibit an encapsulation resin to seal a region retaining the semiconductor element from exuding toward the bottom face side of the package.