A logic diagram search device of the present invention includes a movement amount estimation section, a computation element/signal line correspondence calculation section, and a similarity degree calculation section. The movement amount estimation section estimates a diagram movement amount between a criterion diagram and a comparative diagram based on a coordinates variation amount. The computation element/signal line correspondence calculation section generates correspondence between a signal line in the criterion diagram connecting the computation elements that have been objects of a correspondence generation operation and a signal line in the comparative diagram connecting the computation elements that have been objects of the correspondence generation operation. The similarity degree calculation section calculates the degree of similarity between the criterion diagram and the comparative diagram based on the computation elements and the signal lines for which the correspondence is generated.