Abstract: A pipe connector device able to simply and effectively seal connected members even when using a seal member through which a gas easily permeates is provided. A connector device 1 provides flow paths 7a and 9a for carrying a pressurized gas, is formed by first and second connection members 7 and 9 connected to each other, an O-ring 11 for sealing sealing surfaces S1 and S2 of the connection members 7 and 9, and a material more resistant to permeation of gas through it than the O-ring 11, and has a backup ring 13 having a support surface 13S for supporting the O-ring 11 receiving a pressure difference between the insides and outsides of the connection members 7 and 9 and a tapered surface 19T on which a distance between the sealing surfaces S1 and S2 at a fit position of the backup ring 13 gradually decreases toward a non gas pressurization side.