An electrocardiograph is disclosed. A first electrocardiograph measures a first electrocardiogram waveform with a potential of a first electrode being as a reference potential among a plurality of electrodes. A second electrocardiograph measures a second electrocardiogram waveform with a potential of a second electrode being as the reference potential among the plurality of electrodes. The first electrocardiograph and the second electrocardiograph are switched in a time sharing manner, and the first electrocardiogram waveform and the second electrocardiogram waveform are measured.