A flatbed knitting machine (1,51), in which a pair of needle beds are arranged front and back to face each other, defining a needle bed gap between the needle beds, whereby on each needle bed, needle grooves are formed in which compound needles are accommodated, each compound needle including a needle body having a hook at a front end thereof on the needle bed gap side and a slider having a tongue in the vicinity of a front end on the needle bed gap side, and being able to allow the hook to be opened or closed and also allow the tongue to advance into the needle bed gap beyond the hook by relative displacement of the slider relative to the needle body so that split knit operations are possible, the slider being provided with a first butt at a portion thereof nearer to the needle bed gap and a second butt at a portion thereof far away from the needle bed gap, the first butt and the second butt being spaced from each other, whereby the flatbed knitting machine comprises: a carriage movable in reciprocation along the needle beds, and a cam system (3,53), for operating the needle body and the slider of the compound needled, being equipped on the carriage, whereby the cam system (3,53) includes; a slider operating cam having a bifurcating portion for guiding the second butt of the slider and bifurcating a path of the slider, depending on whether the second butt is sunk in the needle groove or not, into a first path which allows the slider to be retreated from the needle bed gap together with the needle body and a second path which allows the slider to be kept in position in the needle bed gap even when the needle body is retreated from there, so as to be actuated for the split knit operation, and characterised in that it comprises a change over presser (23a, 23b) which is located at a position in the vicinity of the slider operating cam where the change over presser can press the first butt of the slider when the second butt of the slider engages the bifurcating portion of the slider operating cam, to allow change over betweenthe operative mode of pressing and the inoperative mode of non-pressing. a carriage movable in reciprocation along the needle beds, and a cam system (3,53), for operating the needle body and the slider of the compound needled, being equipped on the carriage, a slider operating cam having a bifurcating portion for guiding the second butt of the slider and bifurcating a path of the slider, depending on whether the second butt is sunk in the needle groove or not, into a first path which allows the slider to be retreated from the needle bed gap together with the needle body and a second path which allows the slider to be kept in position in the needle bed gap even when the needle body is retreated from there, so as to be actuated for the split knit operation, and characterised in that it comprises a change over presser (23a, 23b) which is located at a position in the vicinity of the slider operating cam where the change over presser can press the first butt of the slider when the second butt of the slider engages the bifurcating portion of the slider operating cam, to allow change over betweenthe operative mode of pressing and the inoperative mode of non-pressing.