Magnetic sensor unit for accurately detecting change of magnetic field

A magnetic sensor unit comprising:

• a magnetic body fixed to a second member that is relatively displaced with respect to a first member;
• at least two magnets fixed to the magnetic body and disposed apart from each other in a relative displacement direction of the second member;
• and
• a magnetic sensor that is fixed to the first member and is configured to detect a change of a magnetic field formed by the at least two magnets, wherein
• the magnetic body has a convex portion protruding between the two magnets,
• the convex portion has abutting portions on which the two magnets abut,
• the magnetic body is provided with concave portions each at a portion to which each magnet is fixed,
• by provision of the concave portions, the convex portion is relatively formed between the two magnets on the magnetic body, and
• each of the concave portions has a depth on a side of the abutting portion deeper than a depth of the other portion thereof.