A power conversion device includes a connector and a sealing member. The connector is connected to a lead-in pipe of a cooling device on the outside of a case. The sealing member makes a watertight seal between a refrigerant flow pipe, which is the lead-in pipe, and the connector. The sealing member includes a connector-side tubular portion, a first watertight seal projection, and a second watertight seal projection. The connector-side tubular portion is located between an inner peripheral surface of the connector and an outer peripheral surface of the lead-in pipe. The first watertight seal projection projects radially outward in an annular shape from the connector-side tubular portion toward the inner peripheral surface of the connector. The second watertight seal projection projects radially inward in an annular shape from the connector-side tubular portion toward the outer peripheral surface of the lead-in pipe.