The barrel (12) of the syringe (1) has a barrel (14) having a tubular part (921) with a threaded projection (925) formed therein, and an inner circumferential surface of the tubular part is a masteur surface (922). A small diameter portion (16) is formed between the liquid reservoir (15) into which the plunger (18) is inserted and the tubular portion (921). The base end (21) of the liquid collection needle (20) is fluid-tightly connected to the small diameter part (16), and the tip of the liquid collection needle (20) projects from the tube tip (14).注入器(1)のバレル(12)の筒先(14)は、螺状突起(925)が形成された管状部(921)を備え、管状部の内周面はメステーパ面(922)である。プランジャ(18)が挿入される貯液部(15)と管状部(921)との間に径小部(16)が形成されている。採液針(20)の基端(21)は径小部(16)に液密に接続され、採液針(20)の先端は筒先(14)から突出している。