According to the exposure amount evaluation method of the embodiment, a photomask including a long-wavelength light reflective film and a mask pattern is set in an EUV exposure apparatus. The long-wavelength light reflective film reflects long-wavelength light having a wavelength longer than that of EUV light and absorbs the EUV light. The mask pattern is formed by an absorption film which is arranged on the upper side of the long-wavelength light reflective film and absorbs the EUV light and the long-wavelength light. A substrate on which resist is coated are set in the EUV exposure apparatus. Exposure light reflected by the photomask is irradiated to the substrate, and a light amount distribution of the long-wavelength light irradiated to the substrate is measured on the basis of an exposure amount of the exposure light irradiated to the substrate.