The present invention addresses the problem of providing a resin end-face butt joint, a method for welding the joints, and a piping member, with which it is possible to ensure a sufficient clamping margin with the clamp of an ordinary welding machine and to ensure an appropriate distance between the centers even when joints having short tubular welding ring parts are welded, and with which it is possible to align the centers by positioning the centers along the same axis. The device for solving this problem is a resin end-face butt joint for which multiple welding ring parts (13, 14) which communicate with a flow path (15) within a joint base part (12) are provided on the joint base part, and fastening parts (18, 19) are provided so as to be coaxial with at least one of these welding ring parts at the outer end of the joint, for the purpose of clamping a welding machine.