A medical system control device comprises a first control unit for controlling at least a power supply to a plurality of devices configuring a medical system, a second control unit, the startup process time of which is longer than the first control unit, for controlling the entire medical system, and a storage unit for storing information at the time of an operation termination process for the medical system, which is performed by the second control unit. The first control unit controls a power supply to a predetermined device among the plurality of devices before the startup process of the second control unit is complete, according to the information stored in the storage unit in response to the power-on of the medical system.