To provide a method for cleaning around an opening segment of a container which is superior in keeping sanitation of food without leaving any cleaning liquid in a V-shaped annular groove formed at a pill far-proof cap.

This method for cleaning around an opening segment of a container is carried out such that the opening segment of a container storing the content is sealingly closed through a packing 11 with a pill far-proof cap C made of synthetic resin which is comprised of a cap main body 1; a tamper evidence band 6 connected to the lower part of a skirt wall 3 of the cap main body 1 through a bridge 5 that can be broken; and an engagement member 7 cooperatively arranged at the inner surface of the tamper evidence band 6 and engaged with an engaging protuberance 13 of the opening segment 10 of a container from below and cleaning liquid is applied in shower to this cap C. Openings 9 are formed in a predetermined circumferential space at the bottom side of a V-shaped annular groove (b) formed by the tamper evidence band 6 and a continuous bellows-like engagement member 7, and cleaning liquid fed around the opening segment 10 of the container is flowed down through an opening 9.