A boron nitride particle having a long and thin shape, in which, when the boron nitride particle is subjected to a loading and unloading test comprising a loading step and unloading step in this order, at least a part of a length in the lateral direction of the boron nitride particle compressed in the loading step returns in the unloading step, in which the loading step includes gradually applying a load from 0.2 mN up to 20 mN at a loading rate of 0.27 mN/second in a lateral direction of the boron nitride particle to compress the boron nitride particle, and the unloading step includes gradually unloading the boron nitride particle to 0.2 mN at an unloading rate of 0.27 mN/second.