The present invention relates to a filtering syringe, and more particularly, to an apparatus obtained by improving a syringe provided with a filter means for filtering foreign substances such as glass fragments of an ampoule, so as to prevent the foreign substances from being injected together with a liquid medicine while allowing the liquid medicine to be smoothly sucked and injected with a small force, especially even though a filter means having micro-pores is employed. The filtering syringe includes an injection needle (10), a cylinder (20) and a plunger (30) and further includes a suction flow passage formed from a pointed hollow cap (100) to the cylinder (20) and provided with a one-way valve means (300)； and an injection flow passage formed from the cylinder (20) to the injection needle (10) and provided with a detachable opening/closing means (400) for selectively opening and closing the injection needle (10) and a filter means (200) for filtering out foreign substances from a liquid medicine, wherein the injection flow passage and the suction flow passage share portions of the flow passages or the injection flow passage is formed independently of the suction flow passage, whereby a flow passage portion from the filter means (200) to the injection needle (10) in the injection flow passage is formed independently of the suction flow passage. The filtering syringe is configured such that the filter means is provided in the injection flow passage to prevent the foreign substances from being injected together with the liquid medicine while enabling the liquid medicine to be more smoothly sucked and injected despite employing the filter means having the micro-pores, thereby maximizing user's convenience and marketability of the syringe.
