To provide a sealing cap, which can be fitted on a container easily, makes it possible to 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 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 projecting stripe 10 on the inner surface 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 screwed off the container unless the connecting means is broken. The locking cylinder 3 is provided with a cutout 15, which widens to facilitate the removal of the cylinder 3, and with a protective cylinder 4, which covers the separation preventive cylinder to prevent the cutout 15 from widening.