A specimen measurement apparatus and method includes sequentially moving individual specimens, radiating first and second radiation beams on first and second positions spaced apart from each other in a moving direction of the specimens, time-serially detecting light components emerging from specimens passing the first and second positions using the same light detector, and an optical selector, arranged in an optical path between the radiation positions and a light detector, for, when a specimen passes the first position, selectively guiding a light component having a first optical characteristic emerging from the specimen to the light detector, and for, when the specimen passes the second position, selectively guiding a light component having a second optical characteristic emerging from the specimen to the light detector.