To provide a luminescent light source that can increase the number of divisions of a reflecting mirror without reducing pitch interval of reflection areas. A luminescent light source comprises a reflecting mirror for reflecting light, a mold unit arranged on a light reflection surface of the reflecting mirror, and light emitting devices of three luminescent devices of red, blue and green that are placed in the central part and output light to the mold unit. In the reflecting mirror, rectangular reflection areas are arranged vertically and horizontally in a grid.