<p>One object of the invention is to provide a plug cap that more reliably prevents the leakage of current by suppressing the ingress of water from a gap between a terminal body and a rubber member. A plug cap 1 includes an electrical connection portion 5 that electrically connects a spark plug to a plug cord, a terminal body 2 that is provided on the outer periphery of the electrical connection portion 5, and a cylindrical rubber member 3 which is mounted on at least one of one end portion and the other end portion of the terminal body 2 and into which the spark plug or the like is inserted. The terminal body 2 includes a one end-side insertion portion 41 which is formed at one end of the terminal body and into which the spark plug is inserted and the other end-side insertion portion 42 which is formed at the other end of the terminal body and into which the plug cord is inserted. The rubber member 3 includes an inner cylindrical portion 31 that is inserted into the one end-side insertion portion 41 or the other end-side insertion portion 42, and a cylindrical outer cylindrical portion 32 that is positioned close to the outer periphery of the inner cylindrical portion 31. The inner cylindrical portion 31 includes annular protrusions 35 that come into contact with the inner peripheral surface of the terminal body 2.</p>
