The present invention provides a power conversion device which can restrain the increase in cost even though on the condition that the power conversion device is used as a switch element of bridge arms while uses a plurality of elements. The power conversion device comprises a grid driving circuit (8)which generates a grid driving signal (A)for controlling the conduction of an IGBT (4a) and an MOSFET (4B) based on a voltage instruction for controlling an AC outputted by an inverter circuit and a triangular wave used as a carrier signal; a grid driving signal selection signal (10) which selects to output one of a first grid driving signal (B) for the IGBT (4a) and a second grid driving signal (C) for the MOSFET based on the frequency of the carrier signal and an output current of the inverter circuit, or to output both the first and second grid driving signals(B,C).