Provided is a plug that enables reliable and easy removal of a plug body together with a cover member from a tubular container without increasing an outwardly-bulging flange portion of a grip part of the plug body and is superior in productivity. A plug 1 for closing an open end of an open-ended tubular container 4. A cover member 3 is fitted on a plug body 2 including a press-fit part 2a and a grip part 2b. An engagement portion 3d is extended from a head plate 3a of the cover member 3 into a recess 2d in the upper surface of the plug body 2 to face an inside wall 2e surrounding the recess 2d. When an external force is applied to incline the head plate 3a with respect to the upper surface of the plug body 2, the engagement portion 3d is engaged to the inside wall 2e.