The present invention provide a high dense aluminum nitride sintered body, a preparing method thereof, and a member for manufacturing semiconductor using the sintered body which has excellent leakage current characteristic, enough adsorbing property, good detachment property and excellent thermal conductivity and so can be applied to even a member for manufacturing semiconductor requiring high volume resistivity like the coulomb type electrostatic chucks as well as the Johnsen-Rahbek type electrostatic chucks.