An erect life-size lens array having a deep focal depth is realized. The erect life-size lens array includes a first lens array, a second lens array and an aperture, and when a thickness of the second lens is ξ1, a refractive index of the second lens is n, a distance between an exit surface of the second lens and a design image surface is ξ2, a radius of a circular hole of the aperture is ra, and a defocus amount is ξ3, the erect life-size lens array is for causing an MTF at a spatial frequency (line-pair/mm) ν to become MTFtarget or more, and satisfies (J1(2π·ra·((n/ξ1)+(1/ξ2))·ν·ξ3))/(π·ra·((n/ξ1)+(1/ξ2))·νξ3)≧MTFtarget, where J1 is a first type first-order Bessel function.