There is provided an apparatus capable of carrying out an accurate bioelectrical impedance measurement by determining whether contact of a living body with electrodes used at the time of the bioelectrical impedance measurement is normal or not more accurately. The apparatus uses a parameter associated with a phase difference in determining the contact condition of the living body with the electrodes. As the parameter associated with a phase difference, the apparatus uses a value represented by X/R wherein R is a resistance component in a bioelectrical impedance to be measured and X is a reactance component in the bioelectrical impedance and determines that contact of the living body with the electrodes is not normal when the value of X/R is out of a determination range such as a