A substrate processing apparatus according to the present disclosure includes first and second nozzles that eject a processing liquid to a substrate; a moving mechanism that moves the first and second nozzles; and a nozzle cleaning device that cleans at least the second nozzle. The nozzle cleaning device includes a cleaning bath and an overflow bath. The cleaning bath includes a liquid storage portion that stores a cleaning liquid for cleaning the second nozzle, and an overflow portion that discharges the cleaning liquid exceeding a predetermined level from the liquid storage portion. The overflow bath is disposed adjacent to the cleaning bath and receives the cleaning liquid discharged from the overflow portion and discharge the received cleaning liquid to the outside.