A light source apparatus is disclosed which allows effective cooling of an arc tube even with a small amount of wind. The light source apparatus has a light emitter and a reflector which reflects light from the light emitter and causes the reflected light to emerge. The light source apparatus also has a wind-guiding member which has a flow inlet and a flow outlet of cooling wind and has a wall portion at a position opposite to the flow inlet, the wall portion guiding the cooling wind toward the light emitter in the reflector. The light source apparatus which has a reflector to which an arc tube is fixed via a connecting member, and has a first flow path on which cooling wind from a fan flows to cool an area of the arc tube closer to the connecting member, and a second flow path on which cooling wind from the fan flows to cool an area of the arc tube closer to a light emitting portion. The second flow path is formed separately from the first flow path.