To provide a screw cutting mechanism that can stably feed screws to a driver bit by stabilizing the position of the screws, and that has an accurate and smooth cutting action. Provided is a screw cutting mechanism for cutting screws one at a time from a screw feeder, wherein: the cutting mechanism is equipped with a rotating disk that rotates horizontally; the outer circumference of the rotating disk comprises a recessed section that opens toward the axis of rotation and holds the screws therein; the rotating disk fits into a circular cavity in the upper section on the frame side; a rotating shaft attaches the rotating disk to the upper section on the frame side, is equipped with a fixed bearing section in the middle section on the frame side, and is equipped with an adjustable bearing section that can be secured to the lower section on the frame body side so that the attachment position is adjustable; a slit disk, which is equipped with a slit that corresponds to the recessed section, and a drive gear are fixed at suitable locations on the rotating shaft between the adjustable bearing section and the rotating disk; a detection mechanism for detecting the slit of the slit disk is provided; a stepping motor is controlled by a detection signal from the detection mechanism to drive the drive gear; and the rotating disk is rotated by a prescribed angle in one direction.