An image projection apparatus comprising: a light modulating element; and an illumination optical system, configured to illuminate the light modulating element with light from a light source, the illumination optical system comprising: an integrator (11a, 11b) configured to divide light from a light source into plural light fluxes, the integrator being constituted of a first fly-eye lens and a second fly-eye lens, in the stated order from the light source; and a collection optical system configured to collect the plural light fluxes from the integrator toward an illumination surface of the light modulating element, the collection optical system being constituted by a first optical unit having a positive optical power and a second optical unit disposed closer to the illumination surface than the first optical unit and having a positive optical power, wherein a rear principal point of the collection optical system is located closer to the light source than a front principal point of the collection optical system, characterized in that the following conditions are satisfied: 1.4 < Fc / Fc − Bk < 3.55 1.31 < F 1 / F 2 < 3.65 5.0 < Fc / Dp < 12.0 2.2 < Fc / ff 2 < 5.45 3 < Bk / Dp < 4.5 0.89 < Fc / F 2 < 0.96 where Fc represents a focal length of the collection optical system, Bk represents an optical distance from a most-illumination surface side optical surface closest to the illumination surface in plural optical surfaces included in the collection optical system to the illumination surface, F1 represents a focal length of the first optical unit, F2 represents a focal length of the second optical unit, Dp represents a diagonal length of a rectangular illumination area on the illumination surface, said diagonal length having a value of 0.7 inches, and ff2 represents a focal length of the second fly-eye lens. a light modulating element; and an illumination optical system, configured to illuminate the light modulating element with light from a light source, the illumination optical system comprising: an integrator (11a, 11b) configured to divide light from a light source into plural light fluxes, the integrator being constituted of a first fly-eye lens and a second fly-eye lens, in the stated order from the light source; and a collection optical system configured to collect the plural light fluxes from the integrator toward an illumination surface of the light modulating element, the collection optical system being constituted by a first optical unit having a positive optical power and a second optical unit disposed closer to the illumination surface than the first optical unit and having a positive optical power, an integrator (11a, 11b) configured to divide light from a light source into plural light fluxes, the integrator being constituted of a first fly-eye lens and a second fly-eye lens, in the stated order from the light source; and a collection optical system configured to collect the plural light fluxes from the integrator toward an illumination surface of the light modulating element, the collection optical system being constituted by a first optical unit having a positive optical power and a second optical unit disposed closer to the illumination surface than the first optical unit and having a positive optical power, wherein a rear principal point of the collection optical system is located closer to the light source than a front principal point of the collection optical system, characterized in that the following conditions are satisfied: 1.4 < Fc / Fc − Bk < 3.55 1.31 < F 1 / F 2 < 3.65 5.0 < Fc / Dp < 12.0 2.2 < Fc / ff 2 < 5.45 3 < Bk / Dp < 4.5 0.89 < Fc / F 2 < 0.96