Planck absolute entropy of the Kerr black hole

The thermal character of the inner horizon of the Kerr black hole is studie d. There is a quantum thermal effect, "Hawking absorption," near the inner horizon. We give a new formulation of the Bekenstein-Smarr formula and rede fine the entropy of the black hole. The redefined entropy must go to zero a s the temperature of the black hole approaches absolute zero. The entropy s atisfies the Nernst theorem, so it can be regarded as the Planck absolute e ntropy of the Ken black hole.