A method is described for checking a value document, wherein measuring values of the value document are detected in spatially resolved fashion. The measuring value detected in the respective measuring point is allocated to a node corresponding to this measuring point, and a two-dimensional network of nodes is formed therefrom. A network is formed from the two-dimensional network of the nodes and a source node and a sink node. By means of the maximally possible flow through the network, the value document is classified as suspected of forgery or not suspected of forgery. The maximally possible flow through the network is a measure for the degree of probability of the value document having a continuous object along a direction transverse to the direction of the network, said object indicating a manipulation of the value document, such as e.g. an adhesive strip or a separating line of a composed forgery.