A chemical liquid injector has syringe adapter 300 removably receiving a cylinder flange formed at a trailing end of cylinder 210 of syringe 200C, 200P, and injection head 110 on which syringe 200C, 200P is mounted with syringe adapter 300 interposed between them. Injection head 110 has adapter receiver 114a opened upward, on which syringe adapter 300 is exchangeably mounted. Syringe adapter 300 has a pair of arm portions located on both sides of left and right of the received cylinder flange and supported to be elastically displaceable so that an interval between the arm portions can be changed.
