The sewing machine includes a presser body, a presser frame, a button holding device including a fixed portion and a sliding portion, a position detecting device including a sliding base attached to the presser frame and a sliding member coupled to the presser body and slidable with respect to the sliding base, a button diameter detecting switch, and a control device. The control device obtains, from the position detecting device, a shift amount of the presser body from a sewing start position when the button diameter detecting switch detects that a sewing operation is carried by a length that corresponds to a diameter of a button, and controls a drive of a sewing needle and the feeding of the workpiece such that a buttonhole stitch corresponding to the diameter of the button is formed.