PURPOSE: To form a projection lens which has a wide view angle while keeping a high aperture ratio and is superior in focusing capacity, by specifying geometrical optical conditions of 5 lenses divided to 5 groups.

CONSTITUTION: A converging lens system consists of two lenses of the third and the fourth groups for the purpose of realizing a high aperture ratio to enhance the aberration compensating capability; and the lens of the second group and the lens of the fifth group whose curved surface are formed to approximately concentric shapes are arranged on both sides of the converging lens system for the purpose of attaining a wide view angle to reduce the occurrence of stigmatism and coma, and their surfaces facing the converging lens system are formed to powerful concaves, and thereby, the Petzval's sum is reduced to compensate curvature of field. The lens of the first group using an aspherical surface is added and one surface of the lens of the third group or the lens of the fourth group is formed to an aspherical surface at least to compensate various aberrations well. Further, the power of the first lens is weakened and one of lenses of the third and the fourth groups is formed with a glass lens to reduce the variance of the focal length due to the variance of refractive index.