A semiconductor apparatus includes a base plate, a metal plate disposed on the base plate, a bonding material disposed between the base plate and the metal plate to be in surface-to-surface contact with the base plate and the metal plate to bond the metal plate to the base plate, an insulating plate disposed on the metal plate, a circuit member disposed on the insulating plate to be in surface-to-surface contact with the insulating plate, a semiconductor device mounted on the circuit member, and an encapsulating material covering the metal plate, the bonding material, the insulating plate, the circuit member, and the semiconductor device to encapsulate an area over the base plate, wherein a bottom face area of the metal plate along the outer perimeter of the metal plate is not covered with the bonding material, wherein the base plate has a groove-shape recess that is disposed along the outer perimeter of the metal plate to face the bottom surface area, wherein the recess has an area having a first depth and a deeper area deeper than the first depth, and the deeper area is disposed beside an inner-side sidewall of the recess, and wherein at least a portion of the deeper area has the bonding material disposed therein.