A power transmission device includes: a planetary gear mechanism; a first rotary machine connected to a sun gear of the planetary gear mechanism; an engine and a one-way clutch that are connected to a carrier of the planetary gear mechanism; a second rotary machine and a drive wheel that are connected to a ring gear of the planetary gear mechanism; and a parking device connected to the ring gear. The power transmission device is configured to positively rotate the first rotary machine at a time a command to disengage the parking device is received and thereafter disengage the parking device, and a direction of the positive rotation is a rotational direction of the carrier rotary-driven by the engine.