Substrate cleaning apparatus

A substrate cleaning apparatus for removing particles adhered to a substrate includes a cleaning chamber for cleaning a substrate under a vacuum atmosphere, a mounting unit, provided in the cleaning chamber, for mounting the substrate thereon. The substrate cleaning apparatus further includes a nozzle unit for injecting a cleaning gas from an area of a higher pressure than an atmosphere in which the substrate is mounted toward the substrate in the cleaning chamber, generating a gas cluster as an aggregate of atoms or molecules of the cleaning gas by adiabatic expansion and irradiating the gas cluster to the substrate in a direction perpendicular thereto, a gas exhaust port for evacuating the cleaning chamber, and a moving unit for relatively moving the mounting unit and the nozzle unit.