The present invention relates to a safety cap which is screwed onto an upper portion of a container body in which contents are stored so as to open/close the outlet of a container. The safety cap of the present invention is configured such that, when an outer cap rotates in a closing direction, a stopper protrusion of the outer cap is brought into contact with a protrusion of an inner cap and the outer cap and the inner cap rotate together, thus enabling the container to be easily closed and automatically capped during a manufacturing process.