An error detection device includes a control unit configured to identify two links that connects a relay communication device to two communication devices as a link pair, identify, from pluralities of inspection devices under the respective two links, a number of inspection devices corresponding to the number N of links where communication errors simultaneously occur (N is an integer of 1 or more) plus 1, determine (N+1) number of inspection flows between the (N+1) number of inspection device pairs, and generate inspection coverage information that includes the determined inspection flows. The error detection device includes a storage unit that stores the inspection coverage information, and a communication unit that sends the inspection coverage information to one device of the inspection device pairs.