There is provided a filter characteristic adjusting apparatus and a filter characteristic adjusting method which can avoid an increase in circuit scale of the filter characteristic adjusting apparatus, and can speedily adjust a characteristic frequency of the filter to a desired frequency. When performing characteristic adjustment for the filter, the test signal generation unit (31) generates a test signal (s14) which is a pulse signal having the same frequency as the characteristic frequency of the filter (10) on the basis of a reference signal (s17), and a phase-shifted test signal (s14′) that is obtained by shifting the phase of the test signal (s14) by a predetermined amount with a phase shift unit (32) in a control signal generation unit (33) is compared with a filter output signal (s16) that is obtained by inputting the test signal (s14) into the filter (10) to obtain a phase difference between the signals, and then the phase difference is subjected to a binary search to generate a control signal (s11).