PURPOSE: To prevent the damage of a user and to accurately discriminate coins by measuring required time for detecting the highest value data of the material, thickness and diameter of the coins, discriminating the presence/absence of the abnormality of a feeding route and discriminating the kind of the coins.

CONSTITUTION: Sensor parts 2, 3 and 4 outputs the sensing signals of the fed coin to a counter part 6 and the counter part 6 outputs the material, thickness and diameter data of the coin to a microcomputer 1. The microcomputer 1 measures the required time after detecting the highest value data of the material in the data until detecting the highest value data of the diameter. When the required time is equal to or more than a prescribed value, it is judged that the feeding route of the coin is abnormal and the operation of an equipment is stopped. Also, when the required time is less than the prescribed value, the respective highest value data and the required time are compared with the basic data of a memory part 7 and the kind of the coin is discriminated. Thus, the damage of the user is prevented and the coin is accurately discriminated.