A lever switch for safe breaking of a circuit of an exercise apparatus includes two conductive copper pieces spaced apart and stably received within a housing by means of elastic pieces. A rotatable cylinder with two journals is positioned in the area of the contact portion of the conductive copper pieces within the housing. The rotatable cylinder is provided with a contact polygon at one side thereof such that the contact portion of the rotatable cylinder is constantly clamped at the top and bottom ends of the contact polygon. A conductive wire is embedded within the contact polygon. As a result, an insertion lever may fit into the body of the rotatable cylinder for in-place-moving the rotatable cylinder such that the contact polygon is turned to be detached from the conductive wire or to be in contact with the contact portion of the conductive copper pieces for safe breaking and making of a circuit.