PURPOSE: To obtain the exciting coil which is miniaturized, and also, the obtain a stable output by providing two pairs or more of exciting coils whose one pair consists of two pieces of a prescribed size opposed to the direction vertical to the advance direction of a belt by placing the belt between them.

CONSTITUTION: An article 2 to which a magnetic marker 1 is attached is placed on a belt 4 and runs in the direction as indicated with an arrow together with the belt 4. Exciting coils 10a, 10b whose one pair consists of two pieces are placed opposingly in the vicinity of the belt 4 by placing the belt 4 between them, and also, the other pair of exciting coils consisting of 10c and 10d are placed in the same way, and these two pairs of exciting coils are all connected in series, and connected to an amplifier and an AC oscillator. The exciting coils whose one pair consists of two pieces are not limited to two pairs and can be further increased. The diameter of each exciting coil 10a, 10b, 10c and 10d can be set to several cm. In such a way, the miniaturization of the whole article identifying device is realized, and also, a parallel magnetic field in the belt width direction generated by two pairs or more of Helmholtz coils is formed, and the output can further be stabilized.