The connection between the terminals of three-phase electric parts used in a matrix converter is simplified to thereby reduce the inductance between conductors.An AC capacitor (10) and an IGBT (20) are disposed such that the linearly arranged terminals (11) of the AC capacitor (10) and the linearly arranged input terminals (21) of the IGBT (20) are parallel to each other, and also that the three terminals of the AC capacitor (10) and the three input terminals of the IGBT (20) are situated close to each other. A bus bar is formed as a laminate bus bar (100) which can be provided by laminating three plate-shaped bus bars on top of each other. In the respective plate-shaped bus bars, there are provided internal terminals for connecting together the mutually adjoining ones of the three-portion terminals of the AC capacitor (10) and the three-portion input terminals of the IGBT (20), and the mutually adjoining terminals are connected together through the internal terminals.