A multiple-rotation absolute-value encoder of a geared motor, wherein the geared motor (10) reduces the rotational speed of a motor shaft (12) and takes it out from a gear shaft (14) to drive a machine device (15) in an operating range corresponding to two rotations of the gear shaft (14). The multiple-rotation absolute-value encoder (20) fitted to the geared motor (10) is made up of a gear shaft absolute value encoder (30) for detecting the absolute position of the gear shaft (14) and a load side absolute value encoder (50) having a two-pole magnet (51) and a magnetic sensor (52) rotating at a rotational speed reduced to half the rotational speed of the gear shaft (14) through the magnetic gear (40).