A method for checking a value document of a specified value-document type has a window which has a foil region. The measurement values for an ultrasound transmission of the value document are established in a spatially resolved manner, and it is checked while employing the measurement values whether for a specified number of locations in a specified checking region the ultrasound transmission according to a specified criterion is greater than a specified minimum ultrasound transmission that is characteristic of a specified portion, lying outside the checking region, of at least one value document of the specified value-document type.