The light source system includes a plurality of light source modules configured to respectively emit light source lights having optical characteristics different from each other, and an irradiation module to which the light source modules are mechanically and detachably attached. The irradiation module includes a first light guide member, a second light guide member, and a first light conversion unit. The first light guide member has a central axis set in parallel with a central axis of the second light guide member. The first light conversion unit is optically connected to the first light guide member and is optically separated from the second light guide member.
