A TWA measuring electrocardiograph includes: a transformation coefficient storing section configured to store a transformation coefficient for deriving a Franks vector electrocardiogram an electrocardiograph controlling section configured to produce a scalar electrocardiogram from electrocardiographic signals of measurement electrodes adapted to be attached to a subject, and configured to derive the Franks vector electrocardiogram from the scalar electrocardiogram by using the transformation coefficient and a TWA measuring section configured to measure a presence of TWA based on the derived Franks vector electrocardiogram.