ROTATION ANGLE DETECTION DEVICE AND ELECTRIC CONTROL DEVICE

A rotation angle detection device has a magnetic field generation unit rotatably provided integrally with a rotating body that rotates about a rotation axis, a magnetic field detection unit that detects a magnetic field generated by the magnetic field generation unit, and a magnetic field transmission unit that covers a portion of the magnetic field generation unit. The magnetic field generation unit has a first surface, a second surface positioned opposite to the first surface, and a side surface connecting the outer peripheries of the first and the second surfaces. The magnetic field transmission unit includes a first magnetic field transmission unit that covers a portion of the side surface. The magnetic field generated by the magnetic field generation unit includes first and second magnetic field components. The magnetic field detection unit detects the first magnetic field component and the second magnetic field component.