A metal terminal (20) includes an post winding-around portion (23) which is connectable to an electrode post (2) to clasp from an outer side thereof. When a lock lever (25) is pressed down to a locking position, a clasp by the post winding-around portion (23) with respect to the electrode post (2) is set in a locked state. An insulating protective cover (30) is attachable to the metal terminal (20) so as to cover at least an entire connecting portion of the metal terminal (20), connected to the electrode post (2), when a distal end portion of the protective cover (30) is pressed down, while using as a fulcrum a proximal end portion of the protective cover (30) abutted against the post winding-around portion (23), and while causing the lock lever (25) to follow the protective cover (30) so that the lock lever (25) is pressed down to the locking position.