A plug body for chemical container capable of preventing the contact thereof with chemical and preventing ruptured film from falling into the chemical, comprising a valve (1) having an insert hole (3) formed at the center thereof, a cover (2) for holding the valve (1) by covering at least the upper peripheral edge of the valve (1), and a locking means for locking an insert body to the cover (2) by using the edge part of the cover (2) having a fitting hole formed therein when the insert body is inserted into the insert hole (3), wherein the rear surface peripheral part of the valve (1) is held by a pedestal part (5), and a film (4) covering the rear surface of the valve is disposed on the upper surface of the pedestal part (5).