An imaging apparatus includes an illumination light output system that outputs light including wavelength components that are different from each other to living body tissue, an image formation optical system that forms an image of the living body tissue illuminated with the light output from the illumination light output system, and an imaging means that images the living body tissue. The image formation optical system has axial chromatic aberration in which focal length for C line that has a wavelength of 643.8 nm is greater than or equal to 102 when focal length for F line that has a wavelength of 486.1 nm is regarded as 100.