Abstract: A spring unit includes a spring part including multiple plate-shaped leaf springs, a plate-shaped support part and a plate-shaped load part connected to opposite ends of each of the leaf springs in a first direction. Each of the leaf springs is defined by multiple sheet-shaped members laminated on one another in a thickness direction thereof. The multiple sheet-shaped members are bonded together by intermolecular force.

Abstract: The semiconductor device includes: a semiconductor element including a body portion formed in a plate shape, a protection film provided at an outer periphery on one surface of the body portion, and a metal thin film provided adjacently to an inner side of the protection film on the one surface of the body portion; a metal member joined to a surface of the metal thin film on a side opposite to the body portion, by solder; and a mold resin sealing the semiconductor element and the metal member, wherein the surface of the metal thin film on the side opposite to the body portion has, on at least a part of an outer periphery thereof, a projection portion projecting from the surface of the metal thin film, and the solder is not provided on an outer peripheral side from a top of the projection portion.