Abstract: A magnetic sensor device includes a first magnet and a second magnet that are disposed on mutually opposing sides of a conveyance path, and one of poles of the first magnet faces an opposite pole of the second magnet. The first magnet and the second magnet generate a cross magnetic field whose strength in a spacing direction, which is orthogonal to a conveying direction, is within a predetermined range. An AMR element is located in a magnetic field in which the strength of the cross magnetic field in the spacing direction is within a predetermined range, and detects, as change in a resistance value, change in the cross magnetic field caused by an object to be detected. A multilayer board outputs the change in the resistance value detected by the AMR element to a processing circuit.

Abstract: By providing a first magnet and a second magnet on wall surfaces of a hollow section where paper money is conveyed such that different magnetic poles face each other, a gradient magnetic field is formed wherein both a magnetic field component in an opposing direction to the magnets and a magnetic field component in a conveyance direction of the paper money include a zero point. An AMR element is provided between the paper money and the first magnet. The AMR element is enclosed by a multi-layered substrate and covered with resin. The AMR element is provided in an area where the magnetic field intensity is weak, which is where the magnetic field intensity in the gradient magnetic field in the conveyance direction is near zero. The paper money passes through an area where the magnetic field intensity of the gradient magnetic field is strong.