A microneedle unit includes a microneedle having a facing surface that faces a puncture target and an adhering surface opposite to the facing surface, the microneedle having at least one projection formed on the facing surface, a recessed container which houses the microneedle and has an opening that surrounds the microneedle, a cover having a sheet form and being connected to the recessed container, and an adhering structure positioned between the cover and the adhering surface. Upon receiving a force, the recessed container is releasable from the cover with the microneedle being adhered to the cover via the adhering structure. The adhering structure has a first contact surface and a second contact surface. When the projections pierce the puncture target, the second contact surface comes into contact with the puncture target at a position outside the facing surface.