PURPOSE: To judge properness and allow applying to a security system, etc., by operating an entering member and a display member to indicate correspondence to the type of element concerned, entering the requisite code information, and making reference to the reference data.

CONSTITUTION: In conformity to the indication of a liquid crystal display board 107, push button switches 104-106 are pushed to enter pass numbers Y1-Yn for unlocking a door 101. From a data output part 109, the entry information data CA is fed to a judgement part 110. In advance an entry is made into a memory 111, and the reference data ST according to the pushing sequence of the switches 104-106 is given from a conversion part 112 to the judgement part 110. The part 110 compares the entry information data CA with the reference data ST, judges properness, and unlocks an electric lock 102 equipped on the door 701 with emission of a control signal for security X. Thus judgement of the properness takes place with entry of the code information from a small number of entering members, i.e., the push button switches 104-106, and the device can be structured small and the costs be reduced.