An electric power semiconductor device, comprising: - a heat radiation material; - a heat transfer plate having a mounting side, the side of the heat transfer plate opposite to the mounting side being adhered to the heat radiation material through an insulating layer; - an electric power semiconductor element that is disposed between the heat transfer plate and a printed wire board, the rear side of the electric power semiconductor element being adhered to the mounting side of the heat transfer plate; and - the printed wire board being disposed on the mounting side of the heat transfer plate, through the intermediary of a spacer provided on the mounting side, the printed wire board facing the heat transfer plate with a predetermined gap, electrode strips being formed on the side of the printed wire board that is opposite to the side facing the heat transfer plate, and an opening portion being provided in the vicinity of the electrode strips; - a first wiring member (5, 51), extending through the opening portion, one end of which being bonded to a first bonding portion of a main power electrode formed on the front side of the electric power semiconductor element and the other end of which being bonded to a second bonding portion (32p, 32j) on a bonding electrode of a first electrode strip among the electrode strips, - a second wiring member (5, 51), extending through the opening portion, one end of which being bonded to a third bonding portion on a control electrode formed on the front side of the electric power semiconductor element and the other end of which being bonded to a fourth bonding portion (32p, 32j) on a bonding electrode of a second electode strip among the electrode strips, wherein at least part of each of the second bonding portion and the fourth bonding portion is included in a space that extends from the main power electrode to the printed wire board in a direction vertical to the mounting side, and the main power electrode, the control electrode, and the opening portion are arranged in such a way that the first bonding portion and the third bonding portion are included in a space that extends from the opening portion to the main power electrode in the vertical direction; characterised in that: the electric power semiconductor element is a vertical semiconductor element on the rear side of which an electrode is formed, and in that a third wiring member, which extends through the opening portion, electrically connects the heat transfer plate with a bonding portion of a third electrode strip among the electrode strips. - a heat radiation material; - a heat transfer plate having a mounting side, the side of the heat transfer plate opposite to the mounting side being adhered to the heat radiation material through an insulating layer; - an electric power semiconductor element that is disposed between the heat transfer plate and a printed wire board, the rear side of the electric power semiconductor element being adhered to the mounting side of the heat transfer plate; and - the printed wire board being disposed on the mounting side of the heat transfer plate, through the intermediary of a spacer provided on the mounting side, the printed wire board facing the heat transfer plate with a predetermined gap, electrode strips being formed on the side of the printed wire board that is opposite to the side facing the heat transfer plate, and an opening portion being provided in the vicinity of the electrode strips; - a first wiring member (5, 51), extending through the opening portion, one end of which being bonded to a first bonding portion of a main power electrode formed on the front side of the electric power semiconductor element and the other end of which being bonded to a second bonding portion (32p, 32j) on a bonding electrode of a first electrode strip among the electrode strips, - a second wiring member (5, 51), extending through the opening portion, one end of which being bonded to a third bonding portion on a control electrode formed on the front side of the electric power semiconductor element and the other end of which being bonded to a fourth bonding portion (32p, 32j) on a bonding electrode of a second electode strip among the electrode strips,