An aluminum nitride sintered body has excellent thermal shock resistance and strength, and is applicable to a radiating substrate for a power module or a jig for semiconductor equipment employed under a strict heat cycle. The aluminum nitride sintered body contains 0.01 to 5 percent by weight of an alkaline earth metal element compound in terms of an oxide and 0.01 to 10 percent by weight of a rare earth element compound in terms of an oxide, respectively as sintering aids, and a residual amount of carbon in a range from 0.005 to 0.1 percent by weight, thereby suppressing grain growth and improving thermal shock resistance and strength of the sintered body.