Aluminum nitride particles used as a material of an aluminum nitride sintered compact are disclosed. The aluminum nitride particles may have a same crystal orientation. The aluminum nitride particles each have an aspect ratio of 3 or more, a plate-like shape, a planar length of 0.6 μm or more and 20 μm or less, and a thickness length of 0.05 μm or more and 2 μm or less.