An ultrasonic cleaning device includes a drain connecting member adapted to be engaged with a drain hole of a sink, and having a valve seat, a valve member having a valve portion angularly movable relative to the valve seat between an opened position to be disengaged from the valve seat to thereby allow for liquid communication between a reservoir of the sink and the drain hole, and a closed position to be engaged with the valve seat for interrupt the liquid communication, and an ultrasonic generating unit disposed in the valve member for exerting ultrasonic vibration on liquid within the reservoir.