TIRE PNEUMATIC PRESSURE DETECTOR

A tire air pressure detection device includes an ideal driving status calculating portion (3e) and a rotational status value compensating portion (3f). The ideal driving status calculating portion calculates an ideal status value ( beta id) corresponding to a slip value under an ideal driving status without tire slippage. The rotational status value compensating portion calculates an ideal rotational status value under the ideal driving status without tire slip based on the regression line calculated by a regression line calculating portion (3d) and the ideal slip status value calculated by the ideal driving status calculating portion.