An imaging lens includes a front lens group, an aperture stop, and a rear lens group arranged in that order from an object side to an image side. An object-side lens closest to an object within the front lens group and an image-side lens closest to an image within the rear lens group are configured to form only three air lenses therebetween. The air lens is an air gap between an image-side surface of an object-side lens and an object-side surface of an image-side lens. The object-side lens and the image-side lens is adjacent to each other in an optical axis of the imaging lens. The three air lenses include an object-side air lens, an image-side air lens, and an intermediate air lens. The object-side air lens and the image-side air lens is biconvex, and the intermediate air lens is biconcave.