Abstract: We start with Klein-Gordon equation on the background of the Kim-black hole and calculate the free energy and entropy of a scalar field by the-brick-wall method. It is shown that the entropy is not only related to the area of an outer horizon but also is a function of inner horizon's area. Taking some appr oximation, we can obtain that the entropy only is proportional to the area of an outer horizon. Further more, the entropy expressed by location parameter of the outer and inner horizon approaches zero, when the radiation temperature of a black hole approaches zero. This satisfies the Nernst theorem. It can be taken as Planck absolute entropy of a black hole.

Keywords: 
• brick-wall method /
• entropy of black hole /
• Nernst theorem