Provided is a roller, and more particularly, to a rotary shaft of the upper part of a rolling wheel, having an inclined surface formed along the circumference of an outer diametral surface thereof, is inserted into at least one coupling groove formed on a transfer bracket, a thrust member is provided at the upper part of the rotary shaft so as to allow a thrust load to be concentrated on the upper end of the rotary shaft or the thrust member, and a radial member is provided at the inner surface of the coupling groove and the rotary shaft positioned at the lower part of the thrust member, thereby supporting a radial load.