To provide an abnormality detector which is capable of easily performing assembling and maintenance works, surely and sensitively operates, can be repeatingly used and is inexpensive and economical.

This device is constituted of a bracket 3 capable of performing the positioning of a micro switch 1 and a lever 2 with proper accuracy and storing the switch 1 and the lever 2, the micro switch 1 switching a contact by taking a push button in and out, an abnormal detection part 2d capable of being abutted on a projection 4a provided on a vibrator 4 and the lever 2 in which a tip part capable of pressing the push button of the micro switch 1 disposed at a location which is larger than a distance which is abutted on the projection 4a from a center of revolution is integrally molded. Because the projection 4a provided on the vibrator 4 performs motions synchronized with abnormal eccentric reciprocating motions that the vibrator 4 generates when a diaphragm is broken, the projection 4a is abutted on the abnormal detection part of the lever 2, the lever 2 is revolved in the horizontal fixed direction, and at the same time, also the tip part of the lever 2 revolves, the tip part removes from the push button of the micro switch 1 and the push button switches a projecting contact.