A light source apparatus includes an outer casing. A light source member and a light source module having a cooling body which cools the light source member are disposed in the outer casing. A wind tunnel which surrounds a heat pipe unit as the cooling body of the light source module is provided in the outer casing. The wind tunnel includes a wind passage which allows cooling wind to pass through the heat pipe unit. An intake-opening is formed in a surface of the outer casing, and cooling wind is taken into the outer casing from outside thereof through the intake-opening. One end of the wind passage of the wind tunnel is connected to the intake-opening.