A tube end (14) of a barrel (12) of an injector (1) includes a tubular portion (921) on which a spiral projection (925) is formed, and an inner circumferential surface of the tubular portion is a female tapered surface (922). A small-diameter portion (16) is formed between a liquid storing portion (15) into which a plunger (18) is inserted and the tubular portion (921). A base end (21) of a liquid collection needle (20) is fluid-tightly connected to the small-diameter portion (16), and a leading end of the liquid collection needle (20) protrudes from the tube end (14).
