An imaging lens whose optical performance is not deteriorated even in a high-temperature environment, aberrations are satisfactorily corrected, optical length is short, and sufficient back focus is secured. The imaging lens is constituted by comprising a first cemented compound lens (14), an aperture stop (S), a second cemented compound lens (16), and a third cemented compound lens (18) and arranging them in this order from the object side to the image side. In the first cemented compound lens, a first lens L1, a second lens L2, and a third lens L3 are arranged in this order from the object side to the image side, in the second cemented compound lens, a fourth lens L4, a fifth lens L5, and a sixth lens L6 are arranged in this order from the object side to the image side, and in the third cemented compound lens, a seventh lens L7, an eighth lens L8, and a ninth lens L9 are arranged in this order from the object side to the image side. The first lens, the third lens, the fourth lens, thesixth lens, the seventh lens, and the ninth lens are formed of a curable resin material, and the second lens, the fifth lens, and the eighth lens are formed of an optical glass material having a highcuring temperature.