An electrocardiogram electrode pad has elasticity and flexibility and encloses an electrocardiogram electrode to be held in close contact with the skin surface of a man to derive a weak current therefrom. The electrocardiogram electrode pad having a bottom wall to be held in contact with the skin surface of the man and a side wall extending from the edge of the bottom wall to be fitted on the electrode section of electrocardiogram electrode. The side wall has a greater thickness for its free end portion than its intermediate and stem portions. The side wall has a pinch portion projecting from the free end to be pinched when fitting and removing the electrocardiogram electrode pad with respect to the electrocardiogram electrode.