A wafer processing apparatus of an embodiment of the present disclosure may include an equipment front end module (EFEM), a wafer transfer chamber, a wafer processing chamber, and a wafer transfer arm. In addition, the EFEM may include an atmosphere control chamber configured to store a wafer carrier accommodating wafers, an upper air supplier configured to supply air into the atmosphere control chamber, an EFEM chamber under the atmosphere control chamber, a load lock arranged to be vertically overlapped by at least a portion of the EFEM chamber, and an EFEM arm configured to transfer the wafer carrier.