The present invention relates to a filter syringe, and more particularly to a mechanism for improving the system of such a syringe comprising a filter for filtering foreign substances such as ampoule glass fragments in order to prevent contamination of the needle or needle. passage of the injection stream with foreign substances, allowing the liquid medicine to be sucked gently without much force. the filter syringe is composed of a needle 10, a cylinder 20 and a plunger 30, and further includes a suction flow passage from the liquid medicament container to the cylinder 20； a passage of the injection flow from cylinder 20 to needle 10； a filter 200 and a one-way valve 300 arranged in the suction flow passage； and a detachable opening / closing means 400 disposed in the injection flow passageway, where a portion of the suction flow passageway extends from the liquid medicament container to the filter 200, being formed independently of the outer peripheral surface of the needle 10 and the injection flow passage. the filter syringe is configured such that the needle 10 or the injection flow passageway is isolated from the suction flow passage above the filter 200 and where foreign substances may remain mixed with the liquid medicament in such that the filter 200 and the one-way valve 300 responsible for requiring greater force for the suction of the liquid medicament are disposed externally, thus allowing the liquid medicament to be sucked with less force than that employed in a conventional syringe, maximizing the user convenience and commercial viability of the syringe.a presente invenção se refere a uma seringa com filtro, e mais particularmente a um mecanismo para melhorar o sistema dessa seringa compreendendo um filtro para filtragem de substâncias estranhas, tais como fragmentos de vidro de ampola, a fim de evitar a contaminação da agulha ou da passagem do fluxo de injeção com substâncias estranhas, permitindo que o medicamento líquido seja sugado suavemente, sem
