A biomedical electric wave sensor includes a base, a central pole, a dry electrode, a case, and a plurality of ribs. When the central pole lowers down, the ribs radiate and expand outward to push aside the hair of a subject, and the dry electrode exposes from the case and contacts the skin of the subject to measure a physiological electric wave signal from the subject. The present invention may overcome the intervention problem caused by hair and achieve the measurement of biomedical electric wave signal.
