A power conversion device comprising: a plurality of first power semiconductor modules incorporating a series circuit of a first semiconductor device and a second semiconductor device, the series circuit connected in parallel to a series circuit of a first capacitor and a second capacitor which are connected in series to a direct current power supply; a plurality of second power semiconductor modules incorporating a bi-directional semiconductor device connected between a connection point between the first capacitor and the second capacitor and a connection point between the first semiconductor device and the second semiconductor device; and a laminated bus bar connecting main circuit terminals of the plurality of first power semiconductor modules and the plurality of second power semiconductor modules to each other. The laminated bus bar includes a pair of output bas bars disposed at a front side and a back side, respectively so as to facing each other.