To provide an opener that allows for a smaller angle of aperture between members when used even with handle parts and trapping parts of the same size, and further to provide an opener which can be easily and reliably turned so as to remove a plug or a lid, with a hand covering the plug or the lid.

The opener comprises a pair of members 2 and 3. The members respectively have handle parts 4 and 7, trapping parts 5 and 8 for trapping the plug or the lid, and hinge parts 6 and 9. The trapping part is located between the handle part and the hinge part, the pair of members 2 and 3 are hinge-coupled at the hinge parts so as to rotate around a hinge axis between an open position and a closed position, and the hinge parts are projected in the longitudinal directions of the members.