An original reading lens includes a four-group, five-element lens configuration including three positive lenses and two negative lenses, wherein the positive lens is constructed by a glass material of low dispersion, and the negative lens is constructed by a glass material of high dispersion, a partial dispersion .theta. gd is defined by .theta. gd=(ng-nd)/(nF-nc) by a refractive index nd of d line (587.56 nm), a refractive index nc of c line (656.27 nm), a refractive index nF of F line (486.13 nm), and a refractive index ng of g line (435.83 nm), a straight line connecting a coordinate point of a reference glass material K7, K7 (.theta. gd, .nu. d) and a coordinate point of a reference glass material F2, F2 (.theta. gd, .nu. d) on a plane with a coordinate system including the partial dispersion .theta. gd and an Abbe number .nu. d as orthogonal two axes is adopted as a reference line, and a partial dispersion deviation .delta. .theta. gd which is the deviation from the reference line of the partial dispersion .theta. gd of the material is positive in one or more positive lens.