To accurately and easily measure muscle bulk and bone density of a subject, especially the legs thereof.

Feet positioning parts 12L, 12R on a device body part 11 used as a scale has electrodes 14L, 14R for measuring voltage at the heel sides and electrodes 13L, 13R for supplying current at the toe sides. Measuring electrodes 17L, 17R which protrude from both side surfaces of an electrode holding part 20 provided between both feet to make contact with the inner sides of the ankles are placed. The current is applied between both lower legs, and the voltage induced by the current to the regions of the body is measured at the heels and the ankles, and the measured value at each region of the body is obtained. The information on the body composition such as muscle bulk is estimated from the measured value of impedance and information to specify the body such as height and weight by using an estimate equation made by a regression analysis based on data collected by MRI in advance.