Provided is a communication terminal that is capable of securing a route having the finest state while suppressing a bandwidth that is consume by a transmission of a control packet at a low level, when applied in an ad-hoc network which uses an electrical power line. The communication terminal included in the ad-hoc network acquires a plurality of route candidates at the beginning of a data transmission by conducting a broadcast transmission of a route creation packet, and acquires a route having the finest state by conducting an unicast transmission of a route estimation packet to each of the route candidates in each predetermined period.