1. A T-Wave Alternans (TWA) measuring apparatus comprising: an electrocardiograph controlling section which is configured to produce an electrocardiogram from electrocardiographic signals of a subject; and a TWA measuring section which is configured to select a plurality of consecutive waveforms from the electrocardiogram, filter waveforms corresponding to noisy heart beats of the subject from the plurality of consecutive waveforms, and measure a presence of TWA by using the filtered plurality of consecutive waveforms.