A portable terminal device comprises a case 110, oscillator 171, passive element 172, voltage measurement circuit 173 and controller 180. The case 110 comprises an electrode having a surface exposed to the outside, on at least a part of the case 110. The oscillator 171 outputs an A.C. voltage signal. One end of the passive element 172 is connected to the oscillator 171, and the other end is connected to the electrode. The voltage measurement circuit 173 is connected to both ends of the passive element 172, and detects the voltage applied to the passive element 172. The control unit 180 acquires the biological information of a living body based on the voltage detected by the voltage measurement circuit 173 in a state in which an A.C. output from the oscillator 171 and the electrode exposed to the outside is in contact with the living body.
