A precise analysis has been made on the profile of the relief grinding wheel of the type 3 worm hob. Firstly, the type 3 worm thread surface, which is normal to the basic thread surface of the hob, is chosen as the helical cutting face of the type 3 worm hob. Secondly, the axis of the relief grinding wheel for this worm hob is tilted in a three-dimensional direction to the axis of the worm hob. Thirdly, the calculation method for the profile of the relief grinding wheel is obtained. Then, the experimental manufacture of a relief grinding wheel is made by applying this calculation method to a numerical example of the type 3 worm hob. The theories in this analysis are verified by practical relief grinding of the type 3 worm hob with this relief grinding wheel and by the measuring of the profile of the cutting edge of the worm hob. The necessity and the effectiveness of this calculation method are confirmed.