To provide a sewing machine for forming eyelet button holes having a turning function of a needle bar and a looper, in which origin search of a swiveling motor can be performed accurately.

In the sewing machine 10 for forming the eyelet button holes, a swivel base of a needle bar is arranged inside an arm part 2c of a sewing machine frame 2, and a looper base 47 and a swiveling mechanism 60 are arranged inside a bed part 2a. The swiveling mechanism includes the swiveling motor 61, a driving pulley 62 connected to the swiveling motor, a first driven pulley 63 connected to the looper base, a transmission shaft 64 for transmitting rotational force from inside the bed part to the swivel base of the needle bar inside the arm part, a second driven pulley 5 connected to the transmission shaft, and a timing belt 66 for transmitting rotational force from the driving pulley to each of the driven pulleys. Rotation ratios between the driving pulley and the second driven pulley or between the first driven pulley and the second driven pulley are different. Origin detection means 68 and 69 of the swiveling motor are arranged each of the pulleys having different rotation ratios.