To prevent a zigzag-swung embroidery material from coming in contact with a sewing needle.

In first calculation processing S1, a sewing advance direction angle is calculated at which a rotary cylinder 16 is rotated in order to allow the embroidery material T that is guided via the guide lever 25 of a zigzag stitch head H, to be directed in a sewing advance direction, based on sewing data. In second calculation processing S2 and S3, the target rotation angle of the rotary cylinder is calculated by adding or subtracting a swinging angle for zigzag swinging to or from the sewing advance direction angle. The rotary cylinder is rotated in accordance with the calculated target rotation angle. The embroidery sewing machine includes a swinging mechanism for swinging the guide lever with respect to the rotary cylinder in order to perform zigzag swinging, so that the swinging corresponding to the swinging angle of the rotary cylinder may be added to the swinging width of the zigzag swinging performed by the swinging mechanism. Alternatively, whole swinging movements to be required for zigzag swinging may be set based on the swinging angle without swinging the guide lever with respect to the rotary cylinder.