Abstract: Disclosed is a substrate processing apparatus. The substrate processing apparatus includes a head unit including a head having at least one nozzle for ejecting a treatment liquid to a substrate and a cleaning unit that cleans the head, wherein the cleaning unit includes a first cleaning member that sprays a cleaning liquid to the head; and a second cleaning member that forms a suction space in combination with the head when being in close contact with the head, and removes impurities attached to the head by providing a reduced pressure to the suction space.

Abstract: The present invention provides an apparatus for treating a substrate, the apparatus including: a head unit including a head formed with one or more nozzles that discharge a treatment liquid to a substrate; and a head maintenance unit configured to perform maintenance for the head, in which the head maintenance unit may include: a liquid receiving block formed with one or more liquid receiving parts having liquid receiving spaces with open tops; a decompression line fluidly-communicating with the liquid receiving space and configured to provide reduced pressure to the liquid receiving space; and a decompression valve installed in the decompression line.