A treatment system includes a holding section that has a heat generation section for applying thermal energy and holds a living tissue, a signal output section that supplies a drive signal to the heat generation section, a signal detection section that detects the drive signal, a signal extraction section that extracts an extracted signal of a predetermined frequency band from the drive signal detected by the signal detection section, a fault detection section that detects when a precursory phenomenon of a fault of the heat generation section the extracted signal reaches or exceeds a predetermined threshold, and a control section that performs control, when the fault detection section detects the precursory phenomenon, so as to reduce power of the drive signal supplied from the signal output section to the heat generation section.