Vibration sensor

A vibration sensor is revealed. The vibration sensor includes a circuit board, where an accommodation space is disposed thereon. A sensing member is set in the accommodation space, and a groove body with a magnet slidable therein is set on the sensing member. Winding layers are disposed on one side or both sides of the sensing member. Further, a lubricated layer is coated on the groove body, or the groove body is made as a vacuum structure or a fractured structure, for decreasing the friction between the groove body and the magnet. On the other hand, winding layers are coated with a protection layer or stacked layer by layer, for increasing the sensing efficiency of magnetic flux without increasing volume to achieve the behavior of vibration sensing with broadband using the vibration sensor according to the present invention.