Abstract: The safety switch incorporates a substantially cylindrical inertial mass which is horizontally movable in all directions in a cavity of the-body of the switch. The inertial mass has a peripheral edge which is engageable with a cam action by projections of a resetting push button for returning it to a centered position. A base surface of the inertial mass has a central depression for housing the upper end of a push rod and maintaining the push rod in a position corresponding to a first state of the circuit. This base surface also has a concentric annular groove into which, when the inertial mass is in an eccentric position, the push rod enters causing the movable contact member to move to a position corresponding to a second state of the circuit. The switch also includes means for disengaging the push rod from the annular groove under the action of the resetting push button, in order to enable the inertial mass to return to the centered position.