A device for measuring the performance of an optical detector comprising: - a cryostat comprising means for placing it under vacuum and cooling it capable of placing the detector in its anticipated operating conditions; - a holder capable of receiving the detector, secured to the inside of the cryostat; - means for measuring the performance of the detector; and - a screen (12a-12b) arranged around the holder capable of limiting the radiation likely to reach the holder in a wavelength range of the detector; characterized in that the measurement device also comprises: - a single-mode optical fiber in the wavelength range of the detector; the optical fiber being inserted in an opening of the cryostat and comprising: • a first end secured to an opening of the screen (12a-12b), to project a luminous flux onto all or part of the detector; and • a second end, external to the cryostat, intended to receive a luminous flux; and - at least two modules for generating a luminous flux that incorporate a fibered source (23, 33, 43) capable of generating the luminous flux in the second end of the optical fiber; the means for measuring the performance of the detector being capable of measuring said performance according to the luminous flux received on the second end; where a plurality of distinct measurements may be performed by interchanging the module connected on the second end. - a cryostat comprising means for placing it under vacuum and cooling it capable of placing the detector in its anticipated operating conditions; - a holder capable of receiving the detector, secured to the inside of the cryostat; - means for measuring the performance of the detector; and - a screen (12a-12b) arranged around the holder capable of limiting the radiation likely to reach the holder in a wavelength range of the detector; characterized in that the measurement device also comprises: - a single-mode optical fiber in the wavelength range of the detector; the optical fiber being inserted in an opening of the cryostat and comprising: • a first end secured to an opening of the screen (12a-12b), to project a luminous flux onto all or part of the detector; and • a second end, external to the cryostat, intended to receive a luminous flux; and - at least two modules for generating a luminous flux that incorporate a fibered source (23, 33, 43) capable of generating the luminous flux in the second end of the optical fiber; - a single-mode optical fiber in the wavelength range of the detector; the optical fiber being inserted in an opening of the cryostat and comprising: • a first end secured to an opening of the screen (12a-12b), to project a luminous flux onto all or part of the detector; and • a second end, external to the cryostat, intended to receive a luminous flux; and • a first end secured to an opening of the screen (12a-12b), to project a luminous flux onto all or part of the detector; and • a second end, external to the cryostat, intended to receive a luminous flux; and - at least two modules for generating a luminous flux that incorporate a fibered source (23, 33, 43) capable of generating the luminous flux in the second end of the optical fiber; the means for measuring the performance of the detector being capable of measuring said performance according to the luminous flux received on the second end; where a plurality of distinct measurements may be performed by interchanging the module connected on the second end.