Capillary columns (102) pass through and are inserted in a rubber plate (14), held and fixed by elastic force of rubber, and two-dimensionally arranged on a sample injection side. it fixes the capillary columns (102) arranged on a plane in close contact by holding the same with a holder plate (6a) from below and with a rubber plate (16) from above on a detection side. In order to press the capillary columns (102) against the holder plate 6a and fix the same with the rubber plate (16), a holder plate (6b) fixing the rubber plate (16) to the holder plate (6a) on both sides of the arrangement of the capillary columns (102) is provided.