PURPOSE: To surely decide a fact that a passer-by is one person and to secure the sufficient safety by writing weight information of a person who is subject to ID discrimination in an ID card, and setting a fact that a deviation of the weight information and an actual weight measured value is within a prescribed range, as a condition.

CONSTITUTION: Weight information of the person concerned is written in an ID card together with ID information, and under the condition that the ID information which reads it by an ID card reader 3 coincides with the registered contents, and also, a deviation of the read weight information and a measured value by a weight meter 4 is within a prescribed range, electric locks 6, 7 are unlocked. In such a way, since the weight information of a person who is subject to ID discrimination is written in the ID card, and a fact that a deviation of the weight information and an actual weight measured value is within a prescribed range is set as a condition, however light the weight may be, it does not occur that two persons are discriminated as one person, and the safety can be secured.