In order to prevent an increase in size of a power source device in a power supply apparatus adapted to manage multiple flow rate controllers, the power supply apparatus is connected via cables to the multiple flow rate controllers adapted to control fluid flow rates, and manages operations of the flow rate controllers via the cables as well as supplying power to the flow rate controllers, respectively. In addition, the power supply apparatus is configured to include a power supply control part that shifts power supply start timings for at least some of the flow rate controllers.