Disclosed herein is an imaging lens unit, including: a first lens having a positive (+) power; a second lens having a negative (−) power; a third lens selectively having one of a positive (+) and negative (−) power; a fourth lens having a negative (−) power; and a fifth lens having a negative (−) power, wherein the first lens, the second lens, the third lens, the fourth lens, and fifth lens are arranged in order from an object to be formed as an image, and the fourth lens is concave toward an image side.