MAGNETIC SENSOR, ROTATION ANGLE DETECTION APPARATUS, AND BRAKE SYSTEM USING ROTATION ANGLE DETECTION APPARATUS

Magnetic sensor has magnetic field detection element that detects a magnetic field that is generated by magnet that rotates about central axis C; and substrate that has first side P and second side P that is a reverse side of the first side P, wherein second side P includes first slope PK that is inclined with respect to first side P. Magnetic field detection element is provided along first slope PK. Magnet is separated from central axis C and polarities of magnet alternate in a circumferential direction about central axis C. First side P is substantially parallel to central axis C. First slope PK is inclined with respect to first side P by an average angle of . In a plane perpendicular to central axis C, intensity of the magnetic field where magnetic field detection element is positioned changes as magnet rotates, and the relation (1/)×0.8≤≤(1/)×1.2(=sin θ)