series of operations shown in fig4 are automatically executed by only switching the start switch 28 on the control panel 11 39 specifically when the start switch 28 is pressed step s10 it is first checked as to whether or not data to be used are the sewing data step s11 if the data are the sewing data the milling drill 10 is rotated step s12 and the vertical drive mechanism 18 is subsequently driven downwardly whereby the milling drill 10 moves downwards step s13 after the passage of the preset time t1 step s14 the x y unit 4 is actuated at a predetermined low speed on the basis of the sewing data step s15 whereby the slot 8 is created in the cassette 5 in accordance with the sewing pattern the x y unit 4 is stopped at the time when the execution of the sewing data is finished steps s16 and s17 grooving of the slot for one area to be sewed is finished at this time and the vertical drive mechanism 18 is driven upwards immediately after the completion of the grooving operation so that the milling drill 10 moves upwards step s18 after the passage of the preset time t2 the rotation of.