An image pickup apparatus includes an optical system which includes a plurality of lenses, and an image sensor which is disposed at an image position of the optical system, wherein the optical system includes in order from an object side, a first lens having a negative refractive power, an aperture stop, a second lens having a positive refractive power, and a third lens having a positive refractive power, and each of the first lens, the second lens, and the third lens is formed of a material having a refractive index not higher than 1.70, and the following conditional expressions (1), (2), (3), and (4) are satisfied:0<；f3/f2≤；1.7 ； ；(1),0.5<；Φ1L/IH<；3.0 ； ；(2),0.05<；D1R2L/Σd<；0.5 ； ；(3), and−；0.4<；f1/R1L<；0.2 ； ；(4).
