A broadcast station candidate determination unit (52) compares a reception condition of a radio wave with a first reception condition threshold to determine whether to set a frequency of the radio wave as a frequency of a radio broadcast station candidate. An interference station candidate identification unit (54) calculates and identifies a frequency of an intermodulation interference station candidate using a frequency of a strong electric field station. An interference station determination unit (55) compares a reception condition of a radio broadcast station candidate whose frequency is the same as that of an intermodulation interference station candidate with a second reception condition threshold indicating that a reception condition is better than the first reception condition threshold to determine whether the radio broadcast station candidate is an intermodulation interference station or a radio broadcast station.