A microneedle unit including: a microneedle having a facing surface that faces a puncture target which is to be pierced by the microneedle and an adhering surface which is a surface opposite to the facing surface, the microneedle having one or more projections on the facing surface a recessed container that houses the microneedle a cover formed in a plate shape and is connected to the recessed container to close an opening of the recessed container, the cover extending from the adhering surface to an area surrounding the adhering surface and an adhering section that adheres the cover and the adhering surface. The recessed container is configured to be released from the cover in a state where the microneedle is adhered to the cover via the adhering section when receiving a force in a direction separating from the cover, and the adhering section includes a first contact surface that is in contact with the cover and a second contact surface that is in contact with the adhering surface and extends from the adhering surface to an area surrounding the adhering surface so that the second contact surface comes into contact with a portion of the puncture target located in an area surrounding the facing surface when the projections pierce the puncture target.