Aluminum nitride particle

An aluminum nitride particle including: a plurality of planes randomly arranged on a surface of the particle, the plurality of planes being observable in a scanning electron micrograph with 500-times magnification; the plurality of planes including adjacent planes intersecting with each other with an obtuse angle to form a ridge line or a valley line therebetween, wherein the particle has a length L and a breadth D, the length being 20 to 200 [mu]m; a ratio L/D of the length L (unit: [mu]m) to the breadth D (unit: [mu]m) is 1 to 1.25; and at least one of the plurality of planes has an area S (unit: [mu]m2) satisfying S/L ≥ 1.0 [mu]m.