The present invention relates to a filter syringe and, particularly, to a device improving a syringe having a filter means for filtering foreign material such as the glass fragments of an ampoule, so as to prevent the foreign material from being injected together with a liquid medicine and, particularly, to smoothly suction and inject the liquid medicine with less power even if the filter means having a fine air hole size is applied. A known syringe, comprising a syringe needle (10), a cylinder (20), and a plunger (30), comprises: a suction passage including a known one-way valve means (300), and formed to reach the cylinder (20) from a hollow cap (100) having a tip and an injection passage formed to reach the syringe needle (10) from the cylinder (20), and including a detachable opening and closing means (400) for selectively opening and closing the syringe needle (10), and a filter means (200) for filtering the foreign material from the liquid medicine, wherein the injection passage and the suction passage share a part or the injection passage is formed independently of the suction passage such that a passage, which reaches the syringe needle (10) from the filter means (200), of the injection passage is formed independently of the suction passage and the filter means is provided in the injection passage so as to prevent the foreign material from being injected together with the liquid medicine, and even if the filter means having a fine air hole size is applied, the liquid medicine can be more smoothly suctioned and injected such that the user convenience and the marketability of the syringe are maximized.
