A syringe (10) comprises a gasket (3), an outer tube (2) and a plunger (4). The plunger (4) includes a helical rib (44) which is provided on a head portion (42), and the gasket includes a threaded engagement portion (33) that threadedly engages the helical rib, a plunger stopper annular rib (34), and a plunger helical rib formed part housing portion (32). The annular rib (34) comprises a ribless portion (35) for guiding the helical rib that has reached the annular rib to the housing portion. The gasket comprises an intermediate annular rib (37) which is provided between a distal end annular rib (38) and a base end annular rib (39) and in a position to the side of the base end portion of the annular rib (34) and a tip (36c) of a helical projection (36).
