Abstract: A cascade A/D converter configured by connecting in cascade two or more stages of electronic circuits, each stage comprising a comparator to convert an analog input signal to a digital signal, a latch circuit to hold the output of the comparator, a D/A converter to convert the output of the comparator to an analog signal, and a subtractor to subtract the output of the D/A converter from the analog input signal; wherein are provided a waveform composition circuit to compose code changing waveforms in the comparators, a plurality of detecting devices for detecting each vicinity of code changing points for detecting the code changes in the comparators by receiving the changing waveforms in the waveform composition circuit as inputs, and an error correction circuit that rejects noise generated at the code changing points based on the outputs of the detecting devices; whereby errors due to noise are substantially eliminated.