An heart rhythm monitoring device for a vehicle and which determines whether a driver has an arrhythmia includes a vehicle state determining portion that determines whether the vehicle is stopped an electrode arranged ON a steering wheel in a position where the driver grips the steering wheel an electrocardiogram waveform obtaining portion that obtains a first electrocardiogram waveform from the electrode and a signal processing and calculating portion that determines whether the heart rhythm of the driver is erratic based ON the first electrocardiogram waveform. When the vehicle is in motion and the signal processing and calculating portion determines whether the heart rhythm of the driver is erratic based ON the waveform component that is strong with respect to noise in the first electrocardiogram waveform.
