A semiconductor power converter, comprising: a first electrical conductor comprising a first joint surface and a first bottom surface perpendicular to the first joint surface; a second electrical conductor comprising a second joint surface opposed parallel to the first joint surface and a second bottom surface located perpendicular to the second joint surface and flush with the first bottom surface; a plate-shaped first semiconductor element comprising different electrodes on the obverse and reverse surfaces thereof, one of the electrodes being joined to the first joint surface of the first electrical conductor by a first connecting body and disposed parallel to the first joint surface; a plate-shaped second semiconductor element comprising different electrodes on the obverse and reverse surfaces thereof, one of the electrodes being joined to the first joint surface of the first electrical conductor by a second connecting body and disposed parallel to the first joint surface; a first convex electrical conductor joined to the other electrode of the first semiconductor element by a third connecting body and comprising a projection projecting toward the second joint surface; a second convex electrical conductor joined to the other electrode of the second semiconductor element by a fourth connecting body and comprising a projection projecting toward the second joint surface; a junction formed of an electrically conductive metal plate and comprising a first positioning opening in which the projection of the first convex electrical conductor is fitted and a second positioning opening in which the projection of the second convex electrical conductor is fitted and joined to the first and second convex electrical conductors and the second joint surface of the second electrical conductor by a sixth connecting body; a first power terminal comprising a proximal end portion joined to the first joint surface by a fifth connecting body and extending outwardly from the first convex electrical conductor; a second power terminal extending outwardly relative to the second convex electrical conductor from the junction; signal terminals connected to the first semiconductor element; and an envelope which covers and seals the proximal end portion of the first power terminal, a proximal end portion of the second power terminal, a proximal end portion of the signal terminal, and the other members of the semiconductor power converter, the envelope comprising a flat bottom surface which extends perpendicular to the first and second semiconductor elements and in which the first bottom surface of the first electrical conductor and the second bottom surface of the second electrical conductor are exposed. a first electrical conductor comprising a first joint surface and a first bottom surface perpendicular to the first joint surface; a second electrical conductor comprising a second joint surface opposed parallel to the first joint surface and a second bottom surface located perpendicular to the second joint surface and flush with the first bottom surface; a plate-shaped first semiconductor element comprising different electrodes on the obverse and reverse surfaces thereof, one of the electrodes being joined to the first joint surface of the first electrical conductor by a first connecting body and disposed parallel to the first joint surface; a plate-shaped second semiconductor element comprising different electrodes on the obverse and reverse surfaces thereof, one of the electrodes being joined to the first joint surface of the first electrical conductor by a second connecting body and disposed parallel to the first joint surface; a first convex electrical conductor joined to the other electrode of the first semiconductor element by a third connecting body and comprising a projection projecting toward the second joint surface; a second convex electrical conductor joined to the other electrode of the second semiconductor element by a fourth connecting body and comprising a projection projecting toward the second joint surface; a junction formed of an electrically conductive metal plate and comprising a first positioning opening in which the projection of the first convex electrical conductor is fitted and a second positioning opening in which the projection of the second convex electrical conductor is fitted and joined to the first and second convex electrical conductors and the second joint surface of the second electrical conductor by a sixth connecting body; a first power terminal comprising a proximal end portion joined to the first joint surface by a fifth connecting body and extending outwardly from the first convex electrical conductor; a second power terminal extending outwardly relative to the second convex electrical conductor from the junction; signal terminals connected to the first semiconductor element; and an envelope which covers and seals the proximal end portion of the first power terminal, a proximal end portion of the second power terminal, a proximal end portion of the signal terminal, and the other members of the semiconductor power converter, the envelope comprising a flat bottom surface which extends perpendicular to the first and second semiconductor elements and in which the first bottom surface of the first electrical conductor and the second bottom surface of the second electrical conductor are exposed.