A power transmission device includes a synchronous meshing mechanism, a braking mechanism, a shift mechanism, a parking gear, a parking mechanism, and a control unit. In the case where the shift mechanism is switched to a parking range, the control unit performs braking continuation processing for continuing the braking of the braking mechanism (step 4) regardless of a driver's braking operation, inhibits the rotation of the driven gear shaft by the parking mechanism, places a predetermined synchronous meshing mechanism in a connected state as a preparation for starting up the vehicle again, and then ends the braking continuation processing (step 5).