A locking projection is provided on a first electrical component. A locking portion is provided on a second electrical component. The locking portion includes an elastically deflectable flexible portion and a hook portion formed at a distal end of the flexible portion and engageable with the locking projection. A spring portion is provided on the second electrical component so as to be spaced a predetermined distance from the locking portion. When deflection of the flexible portion has reached a predetermined amount or more, the spring portion is depressed by the locking portion so as to be elastically deflected.