To provide a sealing cap, which can be fitted on a container easily, makes it possible to clearly confirm the nonuse of the container before unsealing it, thus available in preventing a fraudulent conduct, can be easily removed from the container after being used up to facilitate the separate disposal of the cap, has a simple structure, and can be manufactured at low costs.

According to the structure of the sealing cap, a locking cylinder 3 is formed to extend downward from the lower end face of a cap body 2 via a breakable connecting means. An engaging projection 10 on the interior of the locking cylinder 3 is engaged with the lower surface of a locking stepped part 11 on the outer circumference of a container mouth 6 so that the cap body cannot be separated from the container unless the connecting means is broken. On the locking cylinder 3, a cutout 15 is formed to widen to facilitate the removal of the cylinder 3, and a sealing plate 4, which can be cut off, is also formed to prevent the widening of the cutout 15.