<p>Provided is a power transmission device which comprises a torque converter, is applied to an idle-stopping vehicle, can improve a fuel efficiency without returning to a fuel cut during the deceleration of the vehicle, and is reduced in cost by eliminating the need of an electric oil pump. The power transmission device comprises an adjustment means (23) which limits the amount of the oil supplied to the torque converter (1) or prohibits the supply of the oil to the torque converter by the oil pump (31) to give a priority to the supply of the oil to a clutch means (3) and a continuously variable transmission (25) when the fuel to an engine (E) is cut off during the deceleration of the vehicle and the vehicle speed is reduced to a predetermined value or less.</p>
