A microneedle unit including a microneedle including a substrate having a first surface and a second surface opposite to the first surface, the microneedle further including a projection protruding from the first surface of the substrate, an adhesive sheet including a sticking region attached to the second surface, the adhesive sheet further including an adhesive region protruding outside the substrate from the sticking region in a direction parallel to the second surface, and a protective sheet covering a portion of the adhesive region outside of the substrate in the direction parallel to the second surface.