Disclosed is an apparatus for measuring biological information and an earphone having the same for contacting with a uniform pressure a user body part using an elastic member. The apparatus includes a first housing a second housing foldably connected with the first housing a third housing foldably connected with the second housing and provided with a sensor for measuring the biological information a plurality of joint parts for connecting the housings to be folded or unfolded to each other one or more locking parts for restraining or releasing the housings to be folded or unfolded to each other and the elastic member for applying the same pressure to make the sensor contact with the users body by enabling the respective housings to be folded or unfolded using a stress-strain.
