To provide a new snap hook device which can attach a lid and a main body without forming gap between them.

This snap hook device consists of a ball side main body 3, a hemispherical socket side main body 6, calking rivets 7 and 8 on the ball side and on the socket side for fixing the ball side main body 3 and the socket side main body 6 respectively, and a stopper plate 10. The ball side main body 3 consists of an engaging protrusion expanding to the center and a flange part formed around the hem of the engaging protrusion. The hemispherical socket side main body 6 consists of an engaging dent 4 formed at the center of the top surface and a clasping spring 5 attached on the surrounding wall of the dent 4 for clasping the engaging protrusion of the ball side main body 3. The stopper plate 10 is calked on the rear surface of the socket side main body 6 with the calking rivets 7, 8 on the socket side, and the diameter of the stopper plate 10 is larger than that of the hem of the socket side main body 6.