To provide a precision copying lens which is provided with a sufficiently large numerical aperture, whose image forming performance is extremely high and the number of lenses is sufficiently small.

This precision copying lens is constituted of a first lens group G1 whose refractive power is positive and a second lens group G2 whose refractive power is positive toward an enlargement magnification side R from a reduction magnification side W. The group G1 is provided with at least one negative lens and at least one aspherical lens surface. Then, the precision copying lens is provided with at least two aspherical lens surfaces as a whole system. Besides, it is provided with the constitution of only one set of double Gauss type lenses having a lens surface (ra) whose convex surface is made to face the reduction magnification side W, a lens surface (rb) whose concave surface is made to face the enlargement magnification side R, a lens surface (rc) whose the concave surface is made to face the reduction magnification side W and a lens surface (rd) whose convex surface is made to face the enlargement magnification side R toward the enlargement magnification side R from the reduction magnification side W in the whole system. Then, constitution of one set of the double Gauss type lenses is arranged in the 2nd lens group G2.