To provide a sewing machine capable of feeding an auxiliary sewn cloth by a prescribed amount every sewing pitch.

The sewing machine comprises a seam forming means for feeding a main to-be-sewn cloth in a prescribed feeding direction in synchronization with the rotation of an arm shaft 11 to form a seam, an eccentric cam mechanism 20 for converting the rotary drive force of the arm shaft 11 to the rocking drive force thereof by way of an eccentric cam 21 provided to the arm shaft 11, an auxiliary sewn cloth feeding mechanism 30 for intermittently feeding an auxiliary sewn cloth, which is sewn to the main sewn cloth, to the sewing position of the seam forming means by the rocking drive force imparted from the eccentric cam mechanism 20, and a phase changing means 40 capable of changing the driving phase of the auxiliary sewn cloth feeding mechanism 30 with respect to the phase of the arm shaft 11.