To provide an automatic resetting electronic component and an assembling method thereof in which assembling of the electronic component having an automatic resetting mechanism can be made easily and surely.

The automatic resetting electronic component is provided with a coil spring 90, a moving body 40 which has a spring member housing portion 49 where the coil spring 90 is housed and is provided with abutting portions 53 where both ends of the coil spring 90 are abutted with both ends of the spring member housing portion 49, a case 10 in which the moving body 40 is assembled and which is provided with locking portions 17 which abut with both ends of the coil spring 90 at positions close to both of the abutting portions of the housed moving body 40, and an electrical function portion composed of a sliding piece 70 or the like which changes an electric output by a sliding movement of the moving body 40. By housing the coil spring 90 in the spring member housing portion 49 and locking both ends of the coil spring 90 with both of the locking portions 17, the moving body 40 is automatically reset to a resetting position. While the moving body 40 is assembled in the case 10, a spring member inserting port 47 into which the coil spring 90 is inserted from outside is provided on the spring member housing portion 49 of the moving body 40.