PROBLEM TO BE SOLVED: To provide a color temperature change filter capable of lowering a color temperature while maintaining color rendering property and an optical module employing the color temperature change filter.SOLUTION: A color temperature change filter (6) has an optical multilayer film. In the color temperature change filter (6), a reflection factor monotonously increases at a shorter wavelength side shorter than 600 nm, and a peak of the reflection factor is between 400 nm and 500 nm. An optical module (100) has: a light source (1); an optical element (4) arranged at a light emitting side of the light source; a phosphor for wavelength conversion (5) applied to a surface of a light source side of the optical element and emitting, regarding light of a first band in the light emitted from the light source as excitation light, fluorescent light of a second band having longer wavelength than the excitation light; a color temperature change filter (6) deposited on a surface on an opposite side of the phosphor for wavelength conversion of the optical element, and configured to reflect part of light in the light emitted from the light source; and a reflector (3) configured to reflect the light reflected at the color temperature change filter toward the phosphor for wavelength conversion.