Provided is a catheter, which can protect a medical personnel and a patient from a needle stick injury when it is disposed of after use. In an example embodiment, the catheter includes a needle, a plug having a front end coupled to the needle, a first case formed to enclose the needle, a socket coupled to a front end of the first case, a gear vertically coupling the first case and the socket to each other and having a tooth formed on an outer periphery of one side and a needle groove formed therein to allow the needle to pass therethrough, a catheter hub fastened by the tooth of the gear, and a tube coupled to the front end of the catheter hub.
