Magnetic sensor device

A magnetic sensor device comprising:

• a magnet;
• a substrate including a magnetic-resistance-effect-element mounted body mounted on a surface thereof opposite to a surface thereof facing the magnet, the magnetic-resistance-effect-element mounted body extending in a longitudinal direction of the magnet;
• a case that accommodates or retains the magnet and the substrate;
• and
• a magnetic shield to cover the case except for the surface of the substrate can which the magnetic-resistance-effect-element mounted body is mounted, wherein
• the magnetic shield comprises:
• a bottom that faces a surface of the case, the surface being disposed so as to oppose the substrate across the magnet, and
• side walls standing from the bottom toward a side adjacent to the substrate, the side walls being spaced from each other in a transverse direction intersecting the longitudinal direction, the side walls extending in the longitudinal direction of the magnet, and
• second side walls standing from the bottom toward the side adjacent to the substrate, the second side walls being spaced from each other in the longitudinal direction, the second side walls extending in the transverse direction,
• the side walls have ends on the side adjacent to the substrate, the ends being located at a same position as the surface of the magnetic substrate facing the magnet or extending more distant from the magnet than the surface of the substrate facing the magnet, and
• the second side walls have ends on the side adjacent to the substrate, the ends being located at a same position as a surface of the magnet opposite to a surface facing the substrate.

The magnetic sensor device according to claim wherein

• the case is formed of an electrically conductive material,
• the magnetic shield is formed of an electrically conductive magnetic material,
• the case is electrically connected to the magnetic shield, and
• the case is grounded.