Provided are a microneedle and a microneedle array which have both aspects of safety and easiness to use and can administer a predetermined dose of a medical agent without causing a pain by smoothly running into the skin surface layer of a patient,the microneedle comprising a frustum and a forward end portion thereon, having a forward end apex angle in the range of 15 to 60° and a forward end diameter in the range of 1 to 20 µm and satisfying the following expression (1),(H: Height of the whole, D: Diameter of bottom surface of the frustum).