A double collar portion formed on a rubber plug intermediate opposite ends thereof and an umbrella-shaped end plug formed at a rear end of the rubber plug improve waterproofing in an electrical terminal. The collar portion is held in intimate contact with an inner peripheral surface of a tubular terminal-receiving chamber to form a seal therebetween. An open end of the tubular terminal-receiving chamber is closed by the end plug without a gap or recess, thereby eliminating the possibility of collection of water and virtually eliminating the possibility of water leaking into the terminal.