1. An information terminal apparatus having a collation function, comprising: an information input unit which has a detection surface exposed outside the apparatus, reads a fingerprint that touches the detection surface, and generates fingerprint data; a control unit which collates fingerprint data input from the information input unit and permits operation of the apparatus; a protection unit which can move to a position where the detection surface of the information input unit is covered and a position where the detection surface is exposed; and a moving mechanism which biases the protection unit to a covering position of the information input unit.