The dimming device includes a pair of input terminals, a bidirectional switch, an inputter, a power supply, a controller, and a current limiter. The power supply is electrically connected between the pair of input terminals and is supplied with electric power from an AC power supply to generate control electric power. The controller is supplied with the control electric power from the power supply to operate. The controller is configured to control the bidirectional switch in accordance with a dimming level. The current limiter stops generation of the control electric power by the power supply when a current larger than or equal to a specified value flows from the AC power supply through the power supply.