SPECTRAL MEASUREMENT DEVICE AND ANALYSIS APPARATUS

A spectral measurement device includes a light reflection grating having a plurality of movable gratings and a movable grating drive unit that displaces the movable gratings to alter a grating pattern of the light reflection grating, a light detecting element that detects light incident on the light reflection grating, a storage unit storing a relationship between a light quantity to be detected by the light detecting element and corresponding light intensities at differing wavelengths for different grating patterns, and a computation unit that calculates light intensities at the differing wavelengths of the light incident on the light reflection grating based on the light quantity of the incident light detected by the light detecting element for each of the different grating patterns by altering the grating pattern based on the relationship between the light quantity and the corresponding light intensities for the different grating patterns stored in the storage unit.