an image pickup lens is provided in which various aberrations are satisfactorily corrected , and the optical length is not more than 6 mm , and moreover a sufficient back focus is secured . this image pickup lens is configured by arranging , in order from the object side , an aperture diaphragm s 1 ; a first lens l 1 having a meniscus shape with concave surface facing the object side , and having positive refractive power ; a second diaphragm s 2 ; and a second lens l 2 having a meniscus shape with concave surface facing the image side , and having negative refractive power . the aperture diaphragm s 1 forms an incidence plane . the second diaphragm s 2 provided between the first lens l 1 and the second lens l 2 is inserted in order to cut out so - called flare , which is light which strikes the peripheral edge of a lens or similar and is irregularly reflected .