A tilt switch includes an insulating housing having a receiving chamber and a connecting cavity between which a ring-shaped step is formed, electrical terminals each having a support arm of platy shape inserted upward into the connecting cavity, a switching ball made of conductive materials and rollably placed in the receiving chamber, and an insulating cover removably covered on the insulating housing to restrain the switching ball in the insulating housing. The support arms are arranged at regular intervals around the center axis of the connecting cavity. The ring-shaped step has a top face substantially perpendicular to two vertical periphery surfaces of the connecting cavity and the receiving chamber. The switching ball needs to roll over the ring-shaped step having a hard span when the tilt switch changes working states thereof among a closed state, a shorted state and an open state.