A machine controller for controlling a machine detects an absolute position of a detection target using a detector outputting rotation number data corresponding to a position of the detection target, and controls the machine based on the detected absolute position of the detection target. The machine controller includes: a storage unit which stores rotation number data, of the detector, that corresponds to a zero point position of the absolute position, as zero point position data, and which stores rotation number data exceeding a rotation number data length that the detector can output, as extended rotation number data; and a calculation unit which calculates the absolute position in accordance with Formula (1) below that is based on the rotation number data output from the detector, the zero point position data, and the extended rotation number data: Absolute position=(Rotation number data from the detector+Extended rotation number data)−Zero point position data   (1).