PURPOSE:To provide a pre-filled syringe capable of reducing the quantity of an injection liquid left in a container as a loss at the time of an injecting action. CONSTITUTION:Vertical ribs 301 having nearly the same height as that of circular ribs 300 and partitioning a circular gap formed between the circular ribs 300 into multiple small gaps are formed between the circular ribs 300 of a moving seal member 3 (or the seal member 2a of a plunger 2 in addition to it).
