Examples of a substrate treatment apparatus include a plurality of load ports, a front-end module adjacent to the plurality of load ports, a plurality of load lock chambers adjacent to the front-end module, the plurality of load lock chambers include a plurality of wafer housing slots, a wafer handling chamber adjacent to the plurality of load lock chambers, a first wafer transfer device in the front-end module, a second wafer transfer device in the wafer handling chamber, and a controller including a processor and a memory configured to cause the processor to execute a program stored in the memory, or including a dedicated circuitry, to issue a command to a wafer moving device to move a wafer between the plurality of load lock chambers when predetermined wafer transfer conditions are satisfied.