A portable electrocardiograph having a display function and method is disclosed. In measuring an electrocardiographic waveform, an electrocardiograph (1) is held in position by a grip including a negative electrode (14) while simultaneously pressing a contact section including a positive electrode (16) against an electrode contact portion other than the right hand of the subject. The measurement result is displayed on a display unit (10) during the measurement operation. The measurement method is divided into the induction mode I in which the contact section including the positive electrode (16) is pressed against the subject's left hand, and the induction mode II in which the contact section including the positive electrode (16) is pressed against the subject's lower left abdomen. In induction mode I, the measurement result is displayed horizontally on the display (10), while in the measurement in mode II, the measurement result is displayed vertically.