To provide a photometric device performing a high precision measurement of the chromaticity and illuminance of a light to be tested even if the incident angle of a light source of an object to be measured (light to be tested) is changed.

The photometric device 1 includes an integrating sphere 2 as a diffusion optic system and measures characteristics of the light source of an object to be measured 100. The integrating sphere 2 includes: an incident part opening 22 which the light from the light source of the object to be measured 100 enters; and a detection part opening 23 through which a diffused light diffused on the internal wall face 21 of the integrating sphere 2 exits to a light detection part 3. The light detection part 3 includes: a spectroscopic means 31 for dispersing the diffused light from the integrating sphere 2, having an incident angle dependent property and disposed near the detection part opening 23; and a photoelectric conversion element row 32 disposed near the spectroscopic means 31, which the light dispersed by the spectroscopic means 31 enters. A diffusion transmission plate 4 is disposed on the incident part opening 22.