An apparatus for attaching a biosignal measurement sensor to a subject including a housing having an open space at one side, an installation portion installed in the open space, on which the biosignal measurement sensor is installed, a plurality of detection electrodes installed at an open side of the housing to contact the subject, and arranged along a circumferential edge of the installation portion to form pairs of detection electrodes facing each other with respect to a center of arrangement, an actuator installed in the housing to rotate and linearly move the installation portion, and a circuit portion searching for the detection electrodes that provide optimal detection data based on a difference in signals between the pairs of detection electrodes, and driving the actuator to allow a pair of sensor electrodes provided at the biosignal measurement sensor to be arranged in the same direction as the searched detection electrodes.