We predicted the broadband noise operating at the maximum efficiency point, that is, the design point of a propeller fan by the wake analysis. The relative flow in the design point separated at the pressure surface. In this case, it was deduced that the flow around the impeller may not interact with the neighbor blade. The blade load was distributed on the blade span widely under the condition of the design point; the velocity fluctuations of the same operation point became large than that of the off-design point. The results of the predicted noise indicated that the influence of the relative velocity on the broadband noise was larger than that of its velocity fluctuation.