To provide a punch data generating device that generates punch data for forming penetrations on a sheet of workpiece with an embroiderable sewing machine to draw a predetermined pattern on the workpiece and/or cut the workpiece along the outline of the pattern, and which effectively prevents any rip when the patterns are drawn on the workpiece, or any uncut portion when cuts are made along the outline.

A specific needle bar 8 of a needle bar case 7 has a punch needle instead of a sewing needle 9. A carriage 19 of a transfer mechanism 18 allows attachment of a holder for holding the sheet of workpiece. A control circuit controls execution of penetration forming operation on the workpiece based on punch data. The control circuit generates draw data for drawing a predetermined pattern on the workpiece through formation of a plurality of penetrations, and cut data for cutting the outline of the pattern created on the workpiece by sequentially forming penetrations along the outline of the pattern, and further modifies the data.