A sensor for checking a value document present in a measuring plane of the sensor, wherein, for checking the value document, the value document and the sensor are moved relative to each other such that the value document moves along a moving direction relative to the sensor, comprising: - an illumination device for illuminating a section of the measuring plane of the sensor, in order to illuminate the value document, when it moves relative to the sensor, in the section with excitation light, and - several detectors (1, 2, 3, n) for detecting luminescence light which the value document illuminated with the excitation light sends out when it moves relative to the sensor, in different detection regions (D1, D2, D3, Dn) of the measuring plane, the detection regions (D1, D2, D3, Dn) of the detectors (1, 2, 3, n) being arranged mutually offset along the moving direction of the value document, and wherein the sensor is adapted to check the decay time of a luminescence of the value document based on luminescence signals of the detectors (1, 2, 3, n), characterized in that - a first one of the detectors is adapted for generating a first luminescence signal (S 1) of a first detection region which in the measuring plane overlaps with the illuminated section such that upon the check of the value document only a partial region of the first detection region is illuminated with excitation light, which partial region is arranged at the beginning of the first detection region, viewed along the moving direction, and - a second one of the detectors is adapted for generating a second luminescence signal of a preceding detection region which is arranged in the measuring plane before the first detection region, viewed along the moving direction, and in the measuring plane overlaps with the illuminated section such that upon the check of the value document only a partial region of the preceding detection region is illuminated with excitation light, which partial region is arranged at the end of the preceding detection region, viewed along the moving direction. - an illumination device for illuminating a section of the measuring plane of the sensor, in order to illuminate the value document, when it moves relative to the sensor, in the section with excitation light, and - several detectors (1, 2, 3, n) for detecting luminescence light which the value document illuminated with the excitation light sends out when it moves relative to the sensor, in different detection regions (D1, D2, D3, Dn) of the measuring plane, the detection regions (D1, D2, D3, Dn) of the detectors (1, 2, 3, n) being arranged mutually offset along the moving direction of the value document, - a first one of the detectors is adapted for generating a first luminescence signal (S 1) of a first detection region which in the measuring plane overlaps with the illuminated section such that upon the check of the value document only a partial region of the first detection region is illuminated with excitation light, which partial region is arranged at the beginning of the first detection region, viewed along the moving direction, and - a second one of the detectors is adapted for generating a second luminescence signal of a preceding detection region which is arranged in the measuring plane before the first detection region, viewed along the moving direction, and in the measuring plane overlaps with the illuminated section such that upon the check of the value document only a partial region of the preceding detection region is illuminated with excitation light, which partial region is arranged at the end of the preceding detection region, viewed along the moving direction.