An aluminum nitride-based ceramic sintered body is provided, which is manufactured by sintering an aluminum nitride powder comprising aluminum nitride as a main component, carbon in an amount of 0.1 wt % or more to 1.0 wt % or less, and containing oxygen in an amount that is not greater than 0.7 wt %, wherein carbon and oxygen are dissolved in grains of the aluminum nitride powder. The a-axis length of the lattice constant of the aluminum nitride is in a range of 3.1120 Å or more to 3.1200 Å or less, and the a c-axis length of the lattice constant is in a range of 4.9810 Å or more to 4.9900 Å or less. The volume resistivity of the aluminum nitride-based ceramic sintered body at 500° C. is 109 Ω·cm or more.