To provide an individual authentification device capable of preventing saturation of characteristic information on finger due to a wide dynamic range of sheet resistance of finger and degradation of authentification ability due to lowering of signal/noise ratio, and capable of exactly discriminating whether the finger is the person himself or the other person.

The device discriminates whether a person to be authentified is the person himself or the other person by providing a wire electrode array 1, on which the finger 2 to be collated of the person to be authentified is placed, successively switching each wire electrode 3 of the wire electrode array 1 by an analog switch 4, calculating distribution of electric resistance value between respective adjacent wire electrodes 3 by partial pressure of the wire electrode array 1 and one kind of reference resistance of plural reference resistance 51 to 5m successively connected with the wire electrode array 1, registering the obtained distribution of resistance value by every plural reference resistance 51 to 5m as plural pieces of characteristic information to be collated, collating the characteristic information with all registered characteristic information in collation and comparing the collating result with a threshold value.