A surgical apparatus (1, 181, 191, 201, 211, 221) includes a probe (11) configured to output energy of treating an organism, and a jaw (17) which can be opened/closed with respect to the probe (11). The surgical apparatus (1, 181, 191, 201, 211, 221) includes an output mode switching section (141, 151, 161, 184, 195, 204, 217, 227) configured to selectively switch an output mode between a bipolar mode in which the probe (11) and the jaw (17) are driven as high-frequency electrodes and a probe single output mode in which the energy is output from only the probe (11) in accordance with an open/closed state of the jaw (17).