An aluminum nitride sintered body containing carbon fibers is provided. This aluminum nitride sintered body is obtained by mixing carbon fibers and aluminum nitride together to form mixed powder, molding the mixed powder to form a compact, and heating and sintering the compact in any of a vacuum atmosphere, an inert atmosphere and a reductive atmosphere. By using electric conductivity and shapes with high aspect ratios of the carbon fibers, continuous electrically conductive paths are formed with a small content of the carbon fibers. In this way, a value of resistance of the aluminum nitride sintered body is reduced.