To stabilize the conveyance of a flexible substrate when the flexible substrate is introduced into and immersed in the cleaning liquid and conveyed under the cleaning liquid and to improve the cleaning effect on the substrate, in a cleaning device for continuously conveying a single wafer type flexible substrate, then immersing the flexible substrate in the cleaning liquid within a cleaning vessel and applying supersonic vibration to the flexible substrate, to clean the substrate.

This cleaning device is provided with means for immersing a flexible substrate 1 in a cleaning liquid 2a within a cleaning vessel 2 and conveying the flexible substrate 1 in a specified direction, namely, plural conveyor wheels 3 for placing the substrate 1 on them and conveying the substrate 1 under the cleaning liquid 2a, and plural jet nozzles 4 each placed opposite to the corresponding one of the conveyor wheels 3. In the cleaning device, the cleaning liquid 2a is sprayed in jet streams from the jet nozzles 4 onto the substrate 1 placed on the conveyor wheels 3, to apply a dynamic pressure to the substrate and to convey the substrate 1 while pressing the substrate 1 against the conveyor wheels 3. Thus, floating-up of the front end of the flexible substrate 1 on the surface of the cleaning liquid 2a and entrainment of air bubbles into the cleaning liquid 2a, can be prevented from being caused when the substrate 1 is introduced into and immersed in the cleaning liquid 2a, and also floating-up of the flexible substrate 1 under the cleaning liquid 2a can be prevented from being caused during the conveyance, to stabilize the conveyance of the substrate 1 and to improve the cleaning effect on the substrate 1.