A light measurement device 1 is a light measurement device for measuring light coming from a sample S, and is provided with a moving-image acquisition part 40 for acquiring moving image data of a two-dimensional light image including light coming from the sample S, and an analysis processing part 51 for performing analysis processing on moving image data. The analysis processing part 51 includes: a luminance-value-data acquisition part 52a for acquiring luminance value data indicating a temporal alteration in a luminance value in a plurality of pixels configuring a region corresponding to a plurality of wells 21 a luminance-value extraction part 52b for extracting a peak value and a bottom value of the luminance value, from the luminance value data and a pixel specifying part 52c for calculating an evaluation value evaluating a state of a change in a luminance value on the basis of the peak value and the bottom value and specifying a target pixel that is to be analyzed from a plurality of pixels on the basis of a repeat state of the evaluation value.
