To provide an aluminum nitride particle having a hexagonal columnar barrel part and bowl-like projection parts at both ends of the columnar part, wherein the long diameter (D) of the barrel part is 10 to 250 μm, the ratio (L1/D) of the distance (L1) between the apexes of the two projection pars to the long diameter (D) of the barrel part is 0.7 to 1.3, and the percentage of the length or thickness (L2) of the barrel part to the distance (L1) between the apexes of the two projection parts is 10 to 60%. The aluminum nitride particle can provide high heat conductivity and excellent electric insulation to a resin when it is filled into the resin.