A cell analyzing device includes a control circuit. The control circuit acquires data of an observation image. The control circuit specifies a colony of a cultured cell in the observation image. The control circuit calculates a ratio at which the cultured cell occupies a predetermined range included in the observation image as an occupancy rate. The control circuit calculates a size of the colony. The control circuit determines a state of the cultured cell based on the occupancy rate and the size of the colony.