To provide a changeover switch enabling a circuit board or the like to be effectively miniaturized without involving reduction of number of fuses and switches and without entailing deterioration of functions.

This changeover switch comprizes a board 11 having contact electrodes 11a, 11b on its inner surface side and equipped with at least a pair of terminals 11A, 11B connected thereto and installed so as to extrude to the exterior, a slider 13 equipped, on the opposite side to the contact electrodes 11a, 11b, with a pair of sliding conductors 13a, 13b sliding on the said contact electrodes 11a, 11b and also equipped with a knob 13A on the reverse side thereof, and a case 12 which houses the slider 13 therewithin, allows a knob 13A part of the slider 13 to project to the exterior so as to be slidable, and holds the board 11 in an integrated manner. And an overcurrent melting element 14, both end parts of which are connected electrically to the pair of sliding conductors 13a, 13b respectively, is provided in the slider 13.