To automate a stile fixing operation of sewing a matting on a stile of a mat bed by providing a mat bed moving member, a matting supply device provided with a chuck member, a tacker to drive in a staple, a cutter to cut the matting, or the like.

A mat bed 5 is mounted on a mounting bed 31 with the front surface turned up side down. After the tip of a matting 6 is set to the cutting position of a cutter 11, the matting 6 is fixed by a chuck member 12. Next, a mat bed moving member 34 is operated to move the mat bed 5 and stop the mat bed when the front end of the mat bed 5 reaches right above a front end bending lever 22. By the rising movement of the lever 22, the tip of the matting 6 is bent upward along a stile of the mat bed 6. Then, a row of tackers 21 is moved rightward to bent horizontally the tip of the matting 6 projecting from the upper surface of the mat bed 5 and then the row of the tackers 21 is lowered to drive in staples. Thereafter, the mat bed 5 is advanced while the matting 6 is drawn out. After the matting 6 is cut off to a predetermined length by a cutter 11, similar working is executed with respect to the rear end of the mat bed 5.