A method as well as a respective checking apparatus for checking a document of value (1), with which the document of value (1) at least in a partial area is illuminated with an intensity (IB) and at different measuring places (2) the intensity (IT) of the light transmitted through the partial area of the document of value (1) and the intensity (IR) of the light reflected by the partial area of the document of value (1) is captured. For eliminating the impact of thickness fluctuations within the document of value and an at the same time simple checking it is provided that the intensities (IT, IR) of the transmitted and reflected light are captured separately, that for each of the different measuring places (2) the sum (IT+IR) of the intensities (IT, IR) of the transmitted and reflected light is calculated, and that the sum (IT+IR) is compared to a predetermined standard value (IS).