A surgical operation system includes a US signal output section, an HV signal output section, a probe having a treatment section which has an HV signal applied thereto and vibrates by ultrasound, an HV signal main control section that performs feedback control of the HV signal output section based on the HV signal, a US signal main control section that performs feedback control of the US signal output section based on a US signal, and an HV signal auxiliary control section that controls the HV signal output section based on the US signal, and has a response time shorter than that of the HV signal main control section.
