A controlling unit includes: a memory unit that stores information in which the multiple clock frequencies that satisfy conditions for predetermined reception interferences to a part of multiple carrier frequencies included in a band frequency of the broadcast wave are previously set so that not all clock frequencies satisfy the conditions for the reception interferences to the same carrier frequencies, the information indicating a relation between each clock frequency and the carrier frequency that includes the reception interference; a reception frequency setting unit that sets the carrier frequency to be received to the broadcast wave receiving unit; a clock frequency determining unit that refers to the information stored in the memory unit and determines a clock frequency that does not include a reception interference to the carrier frequency that is set by the reception frequency setting unit, the determined clock frequency being out of the multiple clock frequencies; and a clock frequency setting unit that sets the clock frequency determined by the clock frequency determining unit to the reference clock generating unit, so that the reference clock generating unit generates a reference clock having the determined clock frequency.