IMAGING LENS

The present invention provides an imaging lens that is small and that can cope with wide shooting field angles while also achieving good optical performance. The imaging lens includes a first lens having a positive refractive power with a convex surface facing the image side, a second lens having a negative refractive power with a concave surface facing the image side in the vicinity of the optical axis, and a third lens having a positive refractive power with a convex surface facing the image side; and a fourth lens having a meniscus shape with a convex surface facing the object side in the vicinity of the optical axis and having a negative refractive power, both sides of the fourth lens forming an aspherical surface and the image side surface having a pole at a position other than the optical axis. If the distance from the object side surface of the first lens to the image side surface of the fourth lens on the optical axis is sigma d and the total optical length is TTL, the following formula is satisfied: 0.5 < sigma d / TTL < 0.9.