A cleaning apparatus 200 is provided with: a treatment tank 10, which defines a treatment space 15 by the inner surfaces (11a, 11b) thereof and on the inner surfaces of which a water-repellent coating has been applied; a cleaning liquid supply device with nozzles 24a (cleaning liquid spray nozzles) for spraying, into the treatment space 15, a mist of a cleaning liquid CL for cleaning surface treatment processing liquid PL adhering to the surface of a metal part S and/or processing liquid PL adhering to the inner surface; and a drying device, which comprises an air compressor 23a and is for supplying drying air compressed by the air compressor 23a to the treatment space 15.