PROBLEM TO BE SOLVED: To house a seal body into a barrel without damage and to prevent a plunger from falling off from the barrel in an injector.SOLUTION: An injector 10 comprises a cylindrical barrel 12 including a discharge port 12c, a seal body 14b coming into close contact with an inner circumferential surface 12e of the barrel 12, a plunger 16 for pushing and moving the seal body 14b to the discharge port side of the barrel 12, and a stopper 16d disposed on one of the barrel 12 and the plunger 16 and coming into elastic contact with the other in a radial direction of the barrel 12.
