Disclosed is an icemaker for a refrigerator, comprising: a tray for containing water to make the water into ice pieces having a predetermined shape; a water supply unit installed at one side of the tray, for supplying water to the tray; a drive unit installed to face the water supply unit with the tray being interposed therebetween; an ice separating lever rotatably assembled between the drive unit and the water supply unit to be rotated by a motor installed in the drive unit; and an ice separating heater for applying heat to the tray so that ice pieces are separated from the tray. The drive unit includes a drive unit housing, a driving motor having a driving gear, a slave gear having a rotary cam and a first magnet and coupled to a rotary shaft of the ice separating lever, a cantilever having a second magnet and rotated by the rotary cam, and first and second Hall elements corresponding to the first and second magnets, respectively.