Apparatus for sewing zip-fasteners on trousers

In the apparatus, a lateral supply section is provided on one side of a fly-conveying passage, and an angle-changing member with a desired inclination angle is provided on the other side of the fly-conveying passage. A fly is supplied from the lateral supply section so as to abut on the angle-changing member and to be displaced at the desired inclination angle, then the fly is conveyed to a sewing section by a first longitudinal conveying belt and a second longitudinal conveying belt provided at a conveying section with the displacement of the fly being maintained. Thereafter, a slide fastener chain is placed and sewn onto the fly, thereby mechanically manufacturing the fly to which the slide fastener chain is sewn diagonally. The thus finished fly with the slide fastener chain is good and uniform in quality while its manufacturing can be efficient.