A spectral characteristic measuring device includes an illuminating unit that illuminates a medium; a light dividing unit that divides reflection light from the medium into reflection light beams; a first imaging unit that includes first lenses and second lenses arranged alternately in a staggered pattern and focuses the respective reflection light beams; a diffraction unit that includes a first diffraction region and a second diffraction region and diffracts the focused reflection light beams to form diffraction images; and a light receiving unit that includes plural pixels for receiving the diffraction images. The reflection light beams focused by the first lenses enter the first diffraction region to form first diffraction images, the reflection light beams focused by the second lenses enter the second diffraction region to form second diffraction images, and the first and second diffraction images are arranged alternately on the light receiving unit in a pixel arrangement direction.