To provide an individual identification information detector with high reliability and convenience capable of being miniaturized and thinned.

This detector is provided with a sensor 111 for detecting individual identification information disposed to a mouse 101 for operating an input tool on a display screen such as a pointer so as to be contacted from the outside, an electrode 112 disposed at the position of the mouse 101 to be easily touched with the hand of a user holding the mouse 101 and a means for supplying ground potential to the electrode 112. Static electricity charged in the user and the static electricity generated by the operation of the mouse 101 are released by the grounded electrode 112 and the individual identification information of a high S/N is detected.