A signal processing apparatus has a plurality of baseline wander correcting units, provided in a processing path in which a predetermined processing is performed on an input signal. At least one of the plurality of baseline wander correcting units includes a correction permission control unit that controls permission or rejection of correction, and baseline wander in the input signal is corrected sequentially by each of the plurality of baseline wander correcting units, based on a control of the correction permission control unit. The baseline wander correcting unit corrects the baseline wander by determining whether or not the baseline correction is to be effected or not, so that the wander of baseline can be efficiently corrected.