A radiative cooling device including: a heat insulating container having an opening portion, and being configured to house an object to be cooled at an interior thereof and thermally insulates the object from an exterior thereof; a far-infrared radiator that is arranged between the object and the opening portion in the heat insulating container, that thermally contacts the object, and that radiates far-infrared rays in a wavelength range of from 8 μm to 13 μm; a far-infrared transmitting window member that closes at least part of the opening portion of the heat insulating container and that transmits the far-infrared rays radiated from the far-infrared radiator; and an intermediate heat insulating member that is arranged between the far-infrared transmitting window member and the far-infrared radiator, that thermally insulates the far-infrared transmitting window member and the far-infrared radiator from each other, and that transmits the far-infrared rays radiated from the far-infrared radiator.