A light source device includes a light source unit configured to emit primary light and an illumination unit configured to optically convert the primary light to secondary light and then emit the secondary light. The light source device further includes a connector configured to allow the light source unit and the illumination unit to be attached to and detached from each other. Furthermore, the light source device includes an information transmitter configured to transmit illumination unit information to the light source unit, the illumination unit information being information regarding the illumination unit.