An image pickup apparatus includes an optical system which includes a plurality of lenses and an aperture stop, 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, a second lens having a negative refractive power, a third lens having a positive refractive power, and a fourth lens, and the following conditional expressions (1) and (3) are satisfied:αmax−αmin<；4.0×10−5/° C. (1), and0.2<；D1Ls/DsF<；3.0 (3).
