A power conversion device implementing an electrical-path-cutoff only if a power semiconductor element short-circuits, and to implement the cutoff at a timing earlier than when a battery fuse fuses, includes a pair of power semiconductor elements configured to be an upper arm element and a lower arm element, being connected in series between a positive-polarity electrode and a negative-polarity electrode; a short circuit detection circuit configured to detect a short circuit in the lower arm element; switching element for fusing, configured to be disposed between positive-polarity-side terminal of upper arm element on the positive-polarity electrode side, and negative-polarity-side terminal of lower arm element on the negative-polarity electrode side, and to be driven to have the positive-polarity-side terminal connected with the negative-polarity electrode when the short circuit is detected; and a cutoff part configured to be made of thin metallic wire for having the negative-polarity-side terminal connected with the negative-polarity electrode.