A slide fastener (1, 2) comprising: a pair of first and second left/right fastener stringers (10a, 10b) in which element rows are disposed on facing tape side edges of first and second fastener tapes having a lengthwise extension and a widthwise extension; and a separable bottom end stop (30, 40) disposed at the ends of the first and second fastener stringers (10a, 10b), the position of the separable bottom end stop (30, 40) relative to the ends of the first and second fastener tapes defining a bottom position of said fastener tapes, and said separable bottom end stop (30, 40) comprising: at least an insert pin (31, 41) attached adjacent to the element row of the first fastener stringer; and a box pin (32, 42) attached adjacent to the element row of the second fastener stringer, one or two sliders (21, 22) moveable in a tape top-bottom direction extending along the length of the tape away from the separable bottom end stop (30, 40) in a so-called top/bottom direction, being characterized in that the insert pin (31, 41) includes a first tapered portion (31b, 41c) including an inclined surface or a curved surface for gradually decreasing a dimension of the insert pin (31, 41) in the tape top/bottom direction toward a facing side edge portion in the tape width direction, the first tapered portion (31b, 41c) being disposed at an upper surface of a corner portion of the insert pin (31, 41) at the box pin (32, 42) side disposed on the facing side edge portion that faces the second fastener stringer in a front end nearer to the element rows when the element rows are at least partially engaged with each other. a pair of first and second left/right fastener stringers (10a, 10b) in which element rows are disposed on facing tape side edges of first and second fastener tapes having a lengthwise extension and a widthwise extension; and a separable bottom end stop (30, 40) disposed at the ends of the first and second fastener stringers (10a, 10b), the position of the separable bottom end stop (30, 40) relative to the ends of the first and second fastener tapes defining a bottom position of said fastener tapes, and said separable bottom end stop (30, 40) comprising: at least an insert pin (31, 41) attached adjacent to the element row of the first fastener stringer; and a box pin (32, 42) attached adjacent to the element row of the second fastener stringer, one or two sliders (21, 22) moveable in a tape top-bottom direction extending along the length of the tape away from the separable bottom end stop (30, 40) in a so-called top/bottom direction, being characterized in that the insert pin (31, 41) includes a first tapered portion (31b, 41c) including an inclined surface or a curved surface for gradually decreasing a dimension of the insert pin (31, 41) in the tape top/bottom direction toward a facing side edge portion in the tape width direction, the first tapered portion (31b, 41c) being disposed at an upper surface of a corner portion of the insert pin (31, 41) at the box pin (32, 42) side disposed on the facing side edge portion that faces the second fastener stringer in a front end nearer to the element rows when the element rows are at least partially engaged with each other. at least an insert pin (31, 41) attached adjacent to the element row of the first fastener stringer; and a box pin (32, 42) attached adjacent to the element row of the second fastener stringer, one or two sliders (21, 22) moveable in a tape top-bottom direction extending along the length of the tape away from the separable bottom end stop (30, 40) in a so-called top/bottom direction, being characterized in that the insert pin (31, 41) includes a first tapered portion (31b, 41c) including an inclined surface or a curved surface for gradually decreasing a dimension of the insert pin (31, 41) in the tape top/bottom direction toward a facing side edge portion in the tape width direction, the first tapered portion (31b, 41c) being disposed at an upper surface of a corner portion of the insert pin (31, 41) at the box pin (32, 42) side disposed on the facing side edge portion that faces the second fastener stringer in a front end nearer to the element rows when the element rows are at least partially engaged with each other.