An incorporated slide fastener, including: an element attaching portion which is extended in a longitudinal direction along one edge and incorporates and fixes respective fastener elements of a zigzag type continuous element row; and a tape main body portion which is extended in a width direction of the tape adjacent to one edge of the element attaching portion, the zigzag type continuous element row being incorporated into opposing edges of a pair of left and right fastener tapes simultaneously with weaving of a fastener tape, wherein the fastener tape is constituted by warps (133, 134, 136) and a weft yarn, in the weft yarn, one thread reciprocates and is weft-inserted in a width direction of the tape in the same opening formed among the warps (133, 134, 136), is returned over fastening warps (133, 134) at a tape edge of the element attaching portion side and sequentially reciprocates and is weft-inserted in a subsequent opening, and the thread is woven by repeating the operation, the fastener element includes an engaging head which is formed from a synthetic resin monofilament and has an engaging portion bulged in a longitudinal direction of the tape in a bending portion bent in a U shape, first and second leg portions (123, 124) which are extended in the width direction of the tape on a first surface and a second surface of the fastener tape with the tape edge from the engaging head, a first connecting portion which connects the first leg portions (123, 123) adjacent to each other in the longitudinal direction of the tape in parallel to the tape surface, and a second connecting portion which connects the second leg portions (124, 124) adjacent to each other in the longitudinal direction of the tape in parallel to the tape surface, the first leg portion disposed on the first surface is fastened by intersections of a plurality of first fastening warps and the weft yarn and the second leg portion disposed on the second surface is fastened by intersections of a plurality of second fastening warps and the weft yarn, characterized in that one constituent thread of the weft yarn in which two constituent threads (135-1, 135-2) reciprocate and are weft-inserted in parallel is incorporated diagonally straddling the first surface of the first leg portion by passing between the first fastening warp and the first leg portion, and one constituent thread in the weft yarn in which two constituent threads reciprocate and are weft-inserted in parallel is incorporated diagonally straddling the second surface of the second leg portion of a subsequent fastener element adjacent by passing between the second fastening warp and the second leg portion. an element attaching portion which is extended in a longitudinal direction along one edge and incorporates and fixes respective fastener elements of a zigzag type continuous element row; and a tape main body portion which is extended in a width direction of the tape adjacent to one edge of the element attaching portion, the zigzag type continuous element row being incorporated into opposing edges of a pair of left and right fastener tapes simultaneously with weaving of a fastener tape, wherein the fastener tape is constituted by warps (133, 134, 136) and a weft yarn, in the weft yarn, one thread reciprocates and is weft-inserted in a width direction of the tape in the same opening formed among the warps (133, 134, 136), is returned over fastening warps (133, 134) at a tape edge of the element attaching portion side and sequentially reciprocates and is weft-inserted in a subsequent opening, and the thread is woven by repeating the operation, the fastener element includes an engaging head which is formed from a synthetic resin monofilament and has an engaging portion bulged in a longitudinal direction of the tape in a bending portion bent in a U shape, first and second leg portions (123, 124) which are extended in the width direction of the tape on a first surface and a second surface of the fastener tape with the tape edge from the engaging head, a first connecting portion which connects the first leg portions (123, 123) adjacent to each other in the longitudinal direction of the tape in parallel to the tape surface, and a second connecting portion which connects the second leg portions (124, 124) adjacent to each other in the longitudinal direction of the tape in parallel to the tape surface, the first leg portion disposed on the first surface is fastened by intersections of a plurality of first fastening warps and the weft yarn and the second leg portion disposed on the second surface is fastened by intersections of a plurality of second fastening warps and the weft yarn, characterized in that one constituent thread of the weft yarn in which two constituent threads (135-1, 135-2) reciprocate and are weft-inserted in parallel is incorporated diagonally straddling the first surface of the first leg portion by passing between the first fastening warp and the first leg portion, and one constituent thread in the weft yarn in which two constituent threads reciprocate and are weft-inserted in parallel is incorporated diagonally straddling the second surface of the second leg portion of a subsequent fastener element adjacent by passing between the second fastening warp and the second leg portion.