An illumination device includes an LED package, an LED driver including an FET, and a thermistor disposed on a substrate. A plurality of such LED packages are disposed on the substrate such that a first area and a second area, each determined by vertices corresponding to LED packages, are defined on the substrate. The thermistor is disposed in the first area, and the FET is disposed in the second area, which is outside of the first area. The thermistor detects a temperature in the first area. Such a configuration allows the thermistor to detect, in accordance with the temperature in the area, the temperature of heat transferred from the LED packages, without being affected by heat generated by the FET. This makes it possible to efficiently make temperature corrections to stabilize color temperature and luminance.