To appropriately correct the fluctuation of the central frequency of an IF filter due to a temperature, etc.

A signal from a two tone generation circuit 2 is inputted to the IF filter 1, an analog current output from a DAC 9 for F0 adjustment is subsequently increased only by a plus one code at a point of time t1, and a comparator 7 performs sampling/hold of a detection output of a bottom peak detector 10. Then, the analog current output from the DAC 9 for F0 adjustment is reduced only by minus two codes at a point of time t2, and the comparator 7 performs sampling/hold. When the two sampled values are compared, and when the latter is larger, data for adjustment supplied to the DAC 9 for F0 adjustment at the point of time t1 is resupplied to the DAC 9 for F0 adjustment to finish an F0 adjustment operation. When the former is larger, the value of the data for adjustment at that time is held to finish the F0 adjustment operation.