A biological signal measuring apparatus (10, 30, 80) comprising: - a first and a second interface (A 111, B 113) for detecting biological signals of an examinee through electrical interfacing with a skin of the examinee; - a first and a second dummy interface (Ad 112, Bd 114) for detecting dummy signals that are different from the biological signals; wherein the first interface (A 111) and the first dummy interface (Ad 112) are placed near to each other, and the second interface (B 113) and the second dummy interface (Bd 114) are placed near to each other, the first dummy interface (Ad 112) having electrical characteristics that are different from those of the first interface (A 111), the second dummy interface (Bd 114) having electrical characteristics that are different from those of the second interface (B 113), the first interface (A 111) comprising a first electrode (A 311, A 811), the second interface (B 113) comprising a second electrode (B 313, B 813), the first dummy interface (Ad 112) comprising a first dummy electrode (Ad 312, Ad 812), the second dummy interface (Bd 114) comprising a second dummy electrode (Bd 314, Bd 814); - a noise extracting unit (12, 32, 82) for extracting a signal, that is proportional to noise generated in the detected biological signals, from the detected biological signals based on the detected biological signals and the detected dummy signals, using the similarity between the fluctuation in the electrical characteristics of the first interface (A 111, A 311, A 811) and the fluctuation in the electrical characteristics of the first dummy interface (Ad 112, Ad 312, Ad 812) and the similarity between the fluctuation in the electrical characteristics of the second interface (B 113, B 313, B 813) and the fluctuation in the electrical characteristics of the second dummy interface (Bd 114, Bd 314, Bd 814); and a biological signal extracting unit (13, 33, 83) for removing the noise from the detected biological signals using the extracted signal, characterized in that the first electrode (A 311, A 811) of the first interface (A 111) comprises a plurality of unit electrodes that are arranged on a substrate, and the first dummy electrode (Ad 312, Ad 818) of the first dummy interface (Ad 112) comprises a plurality of unit dummy electrodes that are arranged on the substrate between the unit electrodes in such a way that the first interface (A 111) and the first dummy interface (Ad 112) are placed near to each other. - a first and a second interface (A 111, B 113) for detecting biological signals of an examinee through electrical interfacing with a skin of the examinee; - a first and a second dummy interface (Ad 112, Bd 114) for detecting dummy signals that are different from the biological signals; wherein the first interface (A 111) and the first dummy interface (Ad 112) are placed near to each other, and the second interface (B 113) and the second dummy interface (Bd 114) are placed near to each other, the first dummy interface (Ad 112) having electrical characteristics that are different from those of the first interface (A 111), the second dummy interface (Bd 114) having electrical characteristics that are different from those of the second interface (B 113), the first interface (A 111) comprising a first electrode (A 311, A 811), the second interface (B 113) comprising a second electrode (B 313, B 813), the first dummy interface (Ad 112) comprising a first dummy electrode (Ad 312, Ad 812), the second dummy interface (Bd 114) comprising a second dummy electrode (Bd 314, Bd 814); - a noise extracting unit (12, 32, 82) for extracting a signal, that is proportional to noise generated in the detected biological signals, from the detected biological signals based on the detected biological signals and the detected dummy signals, using the similarity between the fluctuation in the electrical characteristics of the first interface (A 111, A 311, A 811) and the fluctuation in the electrical characteristics of the first dummy interface (Ad 112, Ad 312, Ad 812) and the similarity between the fluctuation in the electrical characteristics of the second interface (B 113, B 313, B 813) and the fluctuation in the electrical characteristics of the second dummy interface (Bd 114, Bd 314, Bd 814); and a biological signal extracting unit (13, 33, 83) for removing the noise from the detected biological signals using the extracted signal, characterized in that the first electrode (A 311, A 811) of the first interface (A 111) comprises a plurality of unit electrodes that are arranged on a substrate, and the first dummy electrode (Ad 312, Ad 818) of the first dummy interface (Ad 112) comprises a plurality of unit dummy electrodes that are arranged on the substrate between the unit electrodes in such a way that the first interface (A 111) and the first dummy interface (Ad 112) are placed near to each other.