An uneven return current is prevented and increase in a loss is suppressed in a power conversion apparatus at the time of inverter operation. The invention includes first and second transistor switch groups in each of which arms are connected in parallel, and sense resistors for detecting a drain current are connected to the first and second transistor switch groups, and a first drive circuit group and the second drive circuit group include means for monitoring a sense current flowing through the sense resistors and a plurality of delay circuits. Further, rising of the plurality of transistor switch groups is controlled by controlling activation and non-activation of the plurality of delay circuits on the basis of a magnitude of the sense current.