An image-capturing device includes: a first image sensor equipped with first and second image-capturing pixels and first focus detection pixels, each of which receives one of light fluxes formed by splitting subject light having passed through an optical system, the first and the second image-capturing pixels generating first and second color signals respectively and the first focus detection pixels outputting focus detection signals indicating a state of focus detection pertaining to the optical system; and a second image sensor equipped with third image-capturing pixels and second focus detection pixels, each of which receives another light flux, the third image-capturing pixels generating third color signals and the second focus detection pixels outputting focus detection signals, wherein: when n represents a quantity of the first image-capturing pixels, quantities of the second and the third image-capturing pixels, and the first and the second focus detection pixels are n, 2n, 2n and 2n respectively.