A lens driver unit includes a plurality of lens groups including a first lens group and a second lens group, a first lens frame with first and second engaging portions, a second lens frame with a third engaging portion to engage with the first engaging portion, a lens barrel, a first guide element, a second guide element, at least one third guide element, an engaging element, and a drive unit. In an imaging position in which all of the lens groups including the first and second lens groups are placed on an optical axis, the first lens frame is integrally moved with the second lens frame along the optical axis by engagement of the first and third engaging portions while in a contained position, the first lens frame is rotated in a predetermined direction to retreat the first lens group outside an inner diameter of the lens barrel.