PURPOSE: To reduce operation mass of main-and sub-feed tables thus to reduce sewing machine torque and vibration.

CONSTITUTION: A driving shaft 4 provided with main and sub-feed lifting eccentrics 15, 16 onto which main and sub-feed horizontal links 17, 19 are fitted. Main and sub-feed driving cranks 23, 27 are supported on a part of a sewing machine frame, to which main and sub-feed tables are connected, which are connected to main and sub-horizontal links through main and sub-feed links 48, 57. A sub-feed table 35 is slidably interposed between a presser plate 40 mounted on the main feed bar and the top of a slide block held slidably back and forth. Features also include a main feed regulation link 54 connected to the other end of the main feed horizontal link 17, a feed crank connected to the said link 54, a stitch length regulation operation part to rotate it, a sub-feed regulation link 63 connected to the other end of the sub-feed horizontal link, a conversion crank connected to them, a differential regulation operation part to change the position of a pin fitted into a long hole thereof, and a connecting rod by which the conversion crank and feed crank are connected.