Abstract: An automatic sewing machine is disclosed which includes a position control device or a device to align automatically the edges of sheet materials to be joined as they are fed toward the needle. The device comprises a sensor unit for detecting the side edges of the upper and lower sheet materials to be joined, a manipulator unit comprising a pair of upper and lower manipulator arms which displace traversely the upper and lower sheet materials independently of each so as to align the side edges thereof, and a control unit which controls the timing of the operation of the manipulator unit to the operations of various mechanisms of the sewing machine such as an automatic feed reverse mechanism, an automatic thread cutting mechanism and so on. The seam formed is spaced apart from the aligned edges exactly by a predetermined distance or margin which may be selectively varied.