A substrate cleaning apparatus including a self-cleaning device is disclosed. The substrate cleaning apparatus includes a self-cleaning device configured to clean a cylindrical scrub-cleaning tool that is rubbed against a substrate surface. The self-cleaning device includes a cleaning body having an inner circumferential surface that is shaped along an circumferential surface of the scrub-cleaning tool, and at least one cleaning nozzle configured to eject a cleaning fluid toward the circumferential surface of the scrub-cleaning tool through a gap between the circumferential surface of the scrub-cleaning tool and the inner circumferential surface of the cleaning body.