COVER BODY MOUNTING STRUCTURE OF RESIN CONTAINER

A portion of the plastic container T where an opening 7 is provided has a flange portion 7a, and provided are a recess provided annularly along a peripheral edge of the opening 7 at an outside of the plastic container body 2, with an annular member being embedded integrally in the recess, a cover 1 resting against the flange portion to close the opening 7, a seal 14 provided between the flange portion 7a and the cover 1 to prevent a leak, and an annular retainer 9 fastened to the annular member 8 while resting against an external surface of the cover 1. This allows the opening 7 provided in the plastic container T and the cover 1 to be fastened together firmly with excellent and stable hermetical sealing performance.