1. A logic diagram search device comprising: a logic diagram storage section; a supply section; a detection section; a movement amount estimation section; a correspondence generation section; and a similarity degree calculation section, wherein said logic diagram storage section stores a plurality of logic diagrams including a comparative diagram that is a searching object, said supply section supplies a criterion diagram serving as a criterion to be compared with said comparative diagram, in said criterion diagram and said comparative diagram, a plurality of computation elements having one or more types and signal lines connecting said computation elements to each other are indicated, said detection section detects a coordinates variation amount between each of said computation elements in said criterion diagram, and said computation element in said comparative diagram having the type thereof corresponding to the type of said each of said computation elements in said criterion diagram, said movement amount estimation section estimates a diagram movement amount between said criterion diagram and said comparative diagram based on said coordinates variation amount, said correspondence generation section moves said computation element in either one of said criterion diagram and said comparative diagram based on said diagram movement amount, and determines whether or not coordinates and the type of said computation element in said criterion diagram have correspondence with those in said comparative diagram, and generates correspondence, said correspondence generation section generates correspondence between said signal line in said criterion diagram connecting said computation elements that have been objects of a correspondence generation operation, and said signal line in said comparative diagram connecting said computation elements that have been objects of said correspondence generation operation, said similarity degree calculation section calculates the degree of similarity between said criterion diagram and said comparative diagram based on said computation elements and said signal lines for which the correspondence is generated.