A syringe and a syringe set are provided. The syringe can be easily distinguished from other type of syringes by merely seeing a syringe tip portion. The syringe includes the tip portion 15 formed at an end portion of a barrel body into which a medicine is to be filled and has an outer diameter of 4.315 mm to 6 mm, a surrounding wall portion 18 surrounding an outer surface of the tip portion 15 and being arranged in a concentric circle manner with the tip portion 15, and a helical rib 19 formed on an inner surface of the surrounding wall portion 18 or the outer surface of the tip portion 15.本發明提供一種注射器及注射器組。注射器僅藉由視認其前端部便可容易地與其他注射器加以區分。注射器包括：前端部15，其係設置於內部供填充藥劑之筒本體11之端部，且外徑為4.315mm至6mm；周邊壁部18，其係於前端部15之外周與前端部15設置於同心圓上；及螺旋狀肋部19，其係設置於周邊壁部18之內表面或前端部15之外表面。
