Abstract: A needle-shaped projection-including part (1), which is configured to inject a liquid to a target object, the needle-shaped projection-including part including: a plate (111) in which a vertically penetrating discharge hole (114) is formed; one or a plurality of fine needle-shaped projections (112) that project from one face of the plate (111); and a lip portion (113) that is formed at an outer edge portion of the one face of the plate (111), wherein in response to pushing out of the liquid from the discharge hole (114), the liquid spreads in a space defined by the target object, the lip portion (113), and the one face of the plate (111), and the liquid enters the target object through holes formed by the one or plurality of needle-shaped projections (112).

Abstract: The purpose of the present invention is to provide a needle hub unit and the manufacturing method thereof, that enables injection with the least possible waste of a medicinal solution. The present invention is provided with a needle hub, a recess provided in the needle hub and into which a tip portion of an injection cylinder is inserted, an elastic body internally provided in the recess and fills a gap between the tip of the injection cylinder and the recess, and an injection needle inserted into the needle hub and penetrating through the elastic body, whereby the injected medicinal solution passes only through the injection needle, thus the remaining of the medicinal solution in the needle hub is prevented.

Abstract: The purpose of the present invention is to provide an injection needle unit, provided with a plurality of needle pieces, with a simple structure and capable of easy manufacturing. The injection needle unit provided with: a needle base provided with a medicinal solution accommodation space; and a plurality of needle pieces, each of which is attached to the needle base, and a base end of the needle piece communicates to the medicinal solution accommodation space. The needle base is composed of: a needle base body, provided with an opening for opening the medicinal solution accommodation space in the direction orthogonal to the axis directions of the needle pieces; and a lid for enclosing the opening of the needle base body.

Abstract: The purpose of the present invention is to provide an injection needle and an injection device which are capable of adjusting the puncture depth of a needle. The present invention is equipped with: a needle; a needle base holding the needle such that the needle protrudes from the distal end side; and an adjuster provided on the outer periphery of the needle base so as to be movable in the axial direction of the needle base. By adjusting the axial-direction position of the adjuster, the protrusion length of the needle can be adjusted. Consequently, the puncture depth of the needle can be adjusted, and there is no need to prepare a plurality of type of injection needles having different protrusion lengths.