Abstract: To inspect a pneumatic tire for excessively coarse or dense tire cord arrangement in a side wall portion of the tire, a surface irregularity resulting from such improper tire cord arrangement is detected by the use of a capacitance-type distance detector unit positioned in the vicinity of the side wall portion of the tire inflated, wherein one of the tire and the detector units is driven so that the tire and detector unit turn with respect to each other about the center axis of the tire for producing from the detector unit an analog signal which varies with the distance between the outer surface of the detector unit and the tire and wherein the analog signal from the detector unit is processed to detect an improper convexity or concavity in the side wall portion of the tire.