To provide an information device capable of performing the user collation easily without troublesome works such as writing a pass word with an input pen.

An ID number setting portion 12 having a plurality of dials 14 capable of setting a set point arbitrarily by the user is arranged on an input pen 10. And at the main body 21 of the equipment, provided are an insertion hole 23 for receiving the ID number setting portion 12 of the input pen 10, detecting means for detecting a set point indicated by each dial 14(14-1...) and ID number collation means which makes the equipment usable only when the set point indicated by each dial 14 fully coincide with the pre-registered value after collating the set point of each dial 14 with the pre-registered value in the equipment.