A blood glucose level measurement apparatus is a non-invasive measurement apparatus which is mounted on the wrist or the like of a user and performs a measurement by using light. When a biological image is captured in order to acquire a blood vessel pattern, not all light emitting elements emit light (entire surface emission is not performed) but some of the light emitting elements within a light emission range emit light. The light emission range is set to a range centering on an irradiation position (measurement light emitting element) in the previous measurement.