To provide a light source device having a superior heat radiation effect.

A light source device 100 includes: a circular reflection plate 10; an LED module as a light source disposed at the center of the reflection plate 10; and a heat pipe 20 mounted on a face opposite to a reflection face on which the LED module of the reflection plate 10 is disposed. A heat conduction member 30 is fitted to the central portion of the reflection plate 10. The heat pipe 20 is a pipe made of a metal of high heat conductivity such as aluminum, aluminum alloy and copper, and a flow channel is exhausted into vacuum and a liquid (for example, water) of about half of a flow channel volume is charged therein. The heat pipe 20 is reciprocated between the central portion of the reflection plate 10 and a peripheral edge portion, and the LED module is radially disposed at the center.