Provided is a substrate processing apparatus that can reduce power consumption,
while maintaining throughput. In addition to a normal mode in which all units are
activated, the apparatus is provided with an energy saving mode that is selectable.
When the energy saving mode is selected, only essential units that are requisites
for a substrate processing are activated and used in the substrate processing.
If it is necessary to increase process efficiency, any additional unit may be activated
and used in the processing. During standby, only an essential unit can be activated
and the rest is halted, or alternatively, all units may be halted. The transition
to the energy saving mode can occur when the standby state continues for a predetermined
period of time after the normal mode is selected.