An antireflection film includes a multilayer film having six layers, in total, provided between an optical substrate and an adhesion layer. The respective layers of first to sixth layers are laminated in order from one side of the adhesion layer. A refractive index of the antireflection film as a whole is lower than that of the optical substrate and higher than that of the adhesion layer. The first and third layers are low refractive index layers having a refractive index of 1.35 to 1.50 at d line. The second, fourth and sixth layers are middle refractive index layers having a refractive index of 1.55 to 1.85 at the d line. The fifth layer is a high refractive index layer having a refractive index, at the d line, that is in a range of 1.70 to 2.50 and that is higher than that of the middle refractive index layer.