A slide fastener comprising: first and second fastener stringers; and a slider for opening and closing the first and second fastener stringers, each of the first and second fastener stringers comprising: a fastener tape; fastener elements provided along a side edge of the fastener tape; and a front stop provided between a first region of the fastener tape where the fastener elements are not provided at the side edge and a second region of the fastener tape where the fastener elements are provided at the side edge, the front stop including a front surface facing the first region, a rear surface facing the second region, a first side surface extending between the front surface and the rear surface and facing outwardly of the fastener tape, a second side surface extending between the front surface and the rear surface and facing inwardly of the fastener tape, wherein the fastener element includes an engaging portion contactable with a guide column of a slider and a base contactable with a flange portion of the slider, a width of the fastener element, which is equal to a width across the engaging portion and the base, is defined by a first imaginary plane in which points or surfaces of the respective engaging portions at the outer-most position outwardly of the fastener tape are arranged and a second imaginary plane in which points or surfaces of the respective bases at the inner-most position inwardly of the fastener tape are arranged, the first imaginary plane and the second imaginary plane being in parallel one another, the rear region of the first side surface of the front stop of the first fastener stringer is provided with a projected engaging portion projected outwardly of the fastener tape beyond the first imaginary plane, and the rear region of the first side surface of the front stop of the second fastener stringer is provided with a recessed engaging portion recessed inwardly of the fastener tape beyond the first imaginary plane, characterized in that the front stop of the second fastener stringer extends along the side edge of the fastener tape longer than the front stop of the first fastener stringer, and the second side surface of the front stop of each of the first and second fastener stringers includes, from a front region to a rear region thereof, a slant surface extending and being sloped to be closer to the second imaginary plane. first and second fastener stringers; and a slider for opening and closing the first and second fastener stringers, each of the first and second fastener stringers comprising: a fastener tape; fastener elements provided along a side edge of the fastener tape; and a fastener tape; fastener elements provided along a side edge of the fastener tape; and a front stop provided between a first region of the fastener tape where the fastener elements are not provided at the side edge and a second region of the fastener tape where the fastener elements are provided at the side edge, the front stop including a front surface facing the first region, a rear surface facing the second region, a first side surface extending between the front surface and the rear surface and facing outwardly of the fastener tape, a second side surface extending between the front surface and the rear surface and facing inwardly of the fastener tape, wherein the fastener element includes an engaging portion contactable with a guide column of a slider and a base contactable with a flange portion of the slider, a width of the fastener element, which is equal to a width across the engaging portion and the base, is defined by a first imaginary plane in which points or surfaces of the respective engaging portions at the outer-most position outwardly of the fastener tape are arranged and a second imaginary plane in which points or surfaces of the respective bases at the inner-most position inwardly of the fastener tape are arranged, the first imaginary plane and the second imaginary plane being in parallel one another, the rear region of the first side surface of the front stop of the first fastener stringer is provided with a projected engaging portion projected outwardly of the fastener tape beyond the first imaginary plane, and the rear region of the first side surface of the front stop of the second fastener stringer is provided with a recessed engaging portion recessed inwardly of the fastener tape beyond the first imaginary plane, characterized in that the front stop of the second fastener stringer extends along the side edge of the fastener tape longer than the front stop of the first fastener stringer, and the second side surface of the front stop of each of the first and second fastener stringers includes, from a front region to a rear region thereof, a slant surface extending and being sloped to be closer to the second imaginary plane.