A surgical system has an ultrasound treatment instrument having an ultrasound transducer, a power supply apparatus to which the ultrasound treatment instrument is detachably connected, an energy supply section that supplies drive energy to the ultrasound transducer, a clock that measures a present time, a time updating section that regularly outputs the present time, a storage section that stores a final updated time that is updated finally in the present time, and a number of times of use, a time period calculation section that calculates a non-connection time period of the ultrasound treatment instrument to the power supply apparatus, and a processing section that performs processing of generating an update signal that causes the number of times of use to be updated in accordance with a determination result with respect to the non-connection time period and a result of determination with respect to a parameter.