A biosignal measuring apparatus and a method of measuring a biosignal is provided. A biosignal measuring apparatus includes a first interfacing unit including two or more first interfaces configured to detect first signals from a subject, a second interfacing unit including two or more second interfaces and a connecting unit, the second interfaces being configured to detect noise from the subject, the connecting unit being configured to connect the second interfaces, and a biosignal extracting unit configured to extract a biosignal of the subject from the first signals by using signals output from the second interfacing unit.