A method for measuring a brain wave comprises extracting positive and negative peaks from an electrocardiogram (EKG) signal reflecting heartbeat information, and positive peaks from an electroencephalogram (EEG) signal reflecting heartbeat-caused noise information and brain wave information. The positive peaks of the EEG signal are classified into a first peak group and a second peak group based on the positive peaks of the EKG signal. The first peak group is affected more greatly by the heartbeat than by the brain wave, and the second peak group is affected more greatly by the brain wave than by the heartbeat. Noise of the first and second peak groups is removed from the EEG signal.
