INSPECTION METHOD FOR NUMBER OF CARD AND INSPECTION DEVICE

PURPOSE:To provide the inspection method of the number of cards and its inspection device capable of accurately judging whether the required number of cards are surely sealed in an envelope or not in no contact without opening it. CONSTITUTION:Whether the required number of cards exist in an envelope 11 or not after the cards are sealed is judged in this inspection method of the number of cards before the cards each fixed on a mount and having at least a metal foil layer or a metal oxide layer partially or wholly are mailed via direct mail. Electromagnetic waves are radiated to the envelope 11 sealing the cards from the outside, the output wave-form, which is the time-wise change of the output voltage value by the reflected waves or transmitted waves of the electromagnetic waves, is calculated, and the number of the cards existing in the envelope 11 is judged in this inspecting method by an inspection device.