Abstract: The present invention comprises: a first lens having a negative refractive index, the first lens being a meniscus lens wherein the surface facing an object is convex toward the object and the surface facing an image is concave; a second lens having a negative refractive index, the second lens being a meniscus lens wherein the surface facing the first lens is convex toward the first lens and the surface facing the image is concave; a third lens having a negative refractive index, the third lens being a lens wherein the surface facing the image is concave; a fourth lens having a positive refractive index, wherein both surfaces are concave; a fifth lens which is located behind the fourth lens and configured in such a way that a third unit lens having a positive refractive index is bonded with a fourth unit lens having a negative refractive index; and a sixth lens which is biconvex and has a positive refractive index.