Power generation apparatus

A power generation apparatus (100) according to the present invention includes: a first on/off valve (11) provided between a steam generation means (5) and an expander (1) in a circulating channel (6); a bypass channel (10) connected between an area between the steam generation means (5) and the first on/off valve (11) and an area between the expander (1) and a condensing means (3); a second on/off valve (12) provided in the bypass channel (10); a third on/off valve (13) provided between a pump (4) and the steam generation means (5) in the circulating channel (6); and a control means (20) that carries out control for starting and stopping the pump (4) and opening and closing the on/off valves (11, 12, 13). When stopping the pump (4), the control means (20) outputs a control signal that stops the pump (4), a control signal that closes the first on/off valve (11), a control signal that opens the second on/off valve (12), and a control signal that closes the third on/off valve (13), and then, in the case where a predetermined condition has been met, outputs a control signal that closes the second on/off valve (12). With this configuration, the occurrence of cavitation in the pump (4) that circulates the working medium can be suppressed without complicating the structure.