PURPOSE: To satisfactorily execute root-coiling with the relative motion quantity in a Y direction between a needle and a button coincident with a root-coiling length L and to prevent danger that the needle is bent by providing a Y- direction moving quantity commanding means to calculate the Y-direction moving quantity of an XY table based on a signal from a detecting means and to command the moving quantity to a drive control means.

CONSTITUTION: After a button 3 held by a holder is sewn to cloth 2 by a needle 7 of a sewing machine, a button holder 10 is rotated at 90° by an air cylinder 50. At such a time, the button holder 10 is rotated around a straight line P passing through a sewing part 4 on the cloth 2 so that the interval L between the button 3 and cloth 2 can be maintained. Next, based on a command from a microcomputer 70, an XY drive control means 4 executes drive control to an XY table 40 and a sewing machine 9 for root-coiling sewing. However, at such a time, the Y-direction driving quantity and root-coiling number N of the XY table 40 are commanded to the XY drive control means 44 based on a signal from a setting means 60.