A load measuring device of the present invention utilizes a strain gauge (20) capable of measuring the pulling up load of a monocrystalline rod (38) grown by the Czochralski method. The monocrystalline rod (38) is pulled up by a wire rope (36) consisting of multiply strands. The periphery of the hanging wire rope (38) is inscribed on at least part of the semicircular cross-sectional shape of a guide groove (40) near the loosening point of the wire of the guide pully.
