The disclosed wafer processing apparatus includes a vacuum chuck unit configured to adsorb and support a wafer assembly including a wafer; a rotary chuck unit configured to rotate the vacuum chuck unit; a rotating shaft connected to the rotary chuck unit to rotate the rotary chuck unit; a ring cover unit configured to press the wafer assembly such that a processing solution sprayed onto the wafer is not diffused into the vacuum chuck unit; a sealing ring installed in the vacuum chuck unit and configured to support the wafer assembly; and a medium supply unit configured to supply an inspection medium to the vacuum chuck unit such that the inspection medium for identifying damage to the sealing ring flows into the sealing ring.