A microneedle including a projection having a through hole formed in the projection in a direction that the projection extends, and a tubular member having an end surface configured to support the projection when the end surface is pressed against a skin and a fluid is supplied through the through hole of the projection to the skin. The projection has a length H along the direction that the projection extends and the supporting surface has an area S such that a ratio of S/H is in a range of from 2.1 to 10.5.