A lens unit includes a lens barrel, an imaging system arranged therein; a movable part having a movable lens, moved in an optical axis with respect to the lens barrel; a linear actuator for moving the movable part in the optical axis direction; and a biasing plate spring having a holding section that holds the movable part, spring sections that can be resiliently deformed and bias the movable part in the optical axis direction, and attached sections that are attached to the lens barrel, the thickness direction of the plate spring coinciding with the optical axis, wherein the holding section of the biasing plate spring is formed into a circular arc; and at least a portion of the spring sections of the plate spring are formed into a shape extending in a direction substantially along the holding section on the outer peripheral side of the holding section.