Abstract: A flat bed knitting machine comprising a jack disposed in needle slot for controlling the movement of the needle, and selector jack for actuating the jack. The selector jack is tiltable upon being pushed by a selector controllable electrically in accordance with a pattern for lowering its butt out of the camming action. A group of cams for acting on the jack butts comprises tuck cams for advancing needles to a tucking position, and a unit of movable and fixed cams arranged in an inverted V-shape around the tuck cams for advancing needles to a knitting position. A combination of knitting, tucking and non-knitting in one course can be performed by jacks selectable in a preceding step so as to be shifted to a tuck cam acting position, and movable under the movable cams being retracted in a following step so as to engage the tuck cams, by jacks newly selectable so as to engage the cams which advance needles outside of the tuck cams to the knitting position, and by jacks that can be maintained at rest.