Abstract: A power supply system includes: a drone including a propeller, a motor for driving the propeller, a power control unit for supplying the motor, a battery storing electric power, a generator for generating the power, an engine for driving the generator, a fuel tank storing fuel to be supplied to the engine, and a power suppling device for supplying the power generated by the generator to a power supply target; a control unit for controlling various operations of the drone; and an operation management unit for controlling the operations of the drone. Upon receipt of a power supply request, the operation management unit flies the drone to the location of the target. After the drone arrives at the target, the control unit causes the generator to generate the power based on a command from the operation management unit to supply the power to the target via the power suppling device.