An inlet hole capable of inserting a pipe thereinto is formed in a pipe joint body along an axis. Retainer attaching holes for attaching with a retainer that prevents detachment of the pipe are formed in a side surface of the pipe joint body to extend therethrough. These retainer attaching holes are configured symmetrically with respect to an X axis passing through a center of the inlet hole as a symmetrical axis. Thus, a circumference of the inlet hole opens symmetrically, so that the heat shrinkage condition after molding is equalized in the circumferential direction. Accordingly, it is not necessary to process a molding pin for the inlet hole with imbalance of heat shrinkage amount in mind, so that the molding pin becomes easy to process. In addition, the retainer can selectively utilize the retainer attaching holes at two positions, so that selective use depending on installation environment can be achieved.