There is provided a wide angle lens system configured to obtain excellent image forming performance even in a half field angle region of 40 degrees to 50 degrees. A wide angle lens system is constituted of a first lens having a negative refractive power, a light path bending member having no refractive power, a second lens having a positive refractive power, an aperture which adjusts a light amount, a first cemented lens formed by cementing a third lens having a positive refractive power and a fourth lens having a negative refractive power, a fifth lens having a positive refractive power, and an optically equivalent member which functions as a faceplate of an optical low-pass filter and a solid state imaging element.