A heater has a cylindrical metallic shell, a heater body partly disposed in a front end portion of the metallic shell, an electrode disposed in a rear portion of the metallic shell and electrically connected to the heater body, and a terminal adapted to be capped with an electric connector. The terminal includes a terminal body for power supply to the heater body through the electrode and an engaging portion formed on an outer circumferential surface of the terminal body so as to be engageable with the electric connector. The electrode and the terminal body are formed integrally with each other. Such a heater can maintain good electrical conduction from the terminal to the heater body with its simple structure throughout an extended period of time.
