Abstract: A wafer cassette through which a sonic wave is evenly transferred to a substrate in a quartz bath, and a cleaning system adopting the wafer cassette are provided. In the wafer cassette, a hole for evenly transferring the sonic wave to the substrate is formed. The cleaning system includes a vibration plate for generating a sonic wave, placed at the lowest portion of the cleaning system, a sink placed on the vibration plate, a quartz bath placed in the sink and spaced from the bottom of the sink, in which a wafer cassette is placed, a plurality of water supplies for supplying a cleaning solution, placed in the bottom of the quartz bath and a water drain for draining the cleaning solution overflown from the quartz bath, placed on the bottom of the sink, opposite to the water supplies, wherein the vibration plate is placed between the water drain and the water supplies.