To prevent torsion or detent of an O-ring and heighten reliability by making the sealing O-ring interposed between a female member and a male member low friction to be movable in the axial direction of a connector by pressure of a used fluid.

This quick connector 10 for piping removably connects a male member 12 to a female member 11, and fits a hose 13 to the female member 11. An O-ring 15, a collar 16 and an O-ring 17 are inserted in order inside a socket housing 14, a bushing 18 is put on the female member 11 and stopped inside, and further retainer 19 is slidably fitted thereto. The O-rings 15, 17 are made of fluororesin to reduce the coefficient of friction to about 0.5. By this arrangement, even if the male member 12 is moved in the axial direction to the female member 11, the O-rings 15,17 are stopped in fixed positions without being dragged to be moved by the male member, so that sealing ability is not inhibited.