A syringe, a filter assembly for the syringe and a ringer assembly filter and collect impurities mixed with a medicinal fluid, allowing only the medicinal fluid to be injected into a patient. The filter assembly includes a needle holder configured to fix an injection needle at a front end thereof, with a neck part of a cylinder being inserted into a rear end thereof. A filter unit includes a support member formed in a single tube shape having a hollow part. An outer side surface contacts the surrounding of the inner surface of the needle holder. The support member is formed of a head part which forms one or more through holes passing through in the forward and backward directions and formed along the surrounding between the hollow part and the outer edge, and forms a hollow part communicating with the hollow part of the head part