A lighting device is a device that is for supplying current to an LED unit, is connected to a constant current source having output terminals to which a capacitor is connected, and includes: a transistor connected in parallel with the capacitor and connected in series with the LED unit; a modulation circuit (a microcomputer of a modulator, etc.) that causes the transistor to switch ON and OFF based on a signal for visible light communication; and a constant current control circuit that maintains a current flowing through the transistor at a constant current when the current flowing through the transistor is greater than a first predetermined value.