The present invention relates to a container security apparatus which is easily attachable/detachable to/from both opening/closing bars of a container to sense whether the container is opened/closed and transmit the sensed information on whether the container is opened/closed to a remote location, to thereby check whether the container is sealed or not on a real time basis and thus safely transport the container, and to thereby check the current position of the container in transit and check whether or not the container has deviated from a predetermined path on a real time basis.