A body fat measurement device includes a back area electrode group support unit including back area electrodes arranged to contact a back area of a measurement subject, a trunk area dimension measurement unit that detects the width and depth of a trunk area of the measurement subject, a position detection unit that detects a relative positional relationship between the back area electrode group support unit and the trunk area dimension measurement unit, an electrode selection unit that selects specific electrodes, placed in contact with the back area at an area that corresponds to the location of the navel of the measurement subject, from a plurality of electrodes included in a trunk area electrode group, based on the position information detected by the position detection unit, and a body impedance measurement unit that measures a body impedance of the measurement subject using the selected back area electrodes.