An illumination device includes an LED to be connected to a power source via two bases having a pair of terminals. In a glow starter type fluorescent lamp, the illumination device can prevent flow-in of a large current (overcurrent) to a glow starter. In an inverter type fluorescent lamp, the illumination device can detect current between two terminal pins of the bases. The illumination device can also be applied to a rapid start type fluorescent lamp without causing any trouble. A first resistor (171a) having impedance 10O and a first capacitor (172a) are arranged between two terminals of a first pair of terminal pins (15a) while a second resistor (171b) and a second capacitor (172b) are arranged between two terminals of a second pair of terminal pins (15b) so as to make a connection between the two terminals of the first pair of terminal pins (15a) and between the two terminals of the second pair of terminal pins (15b).
