To provide a magnetic core and a coil device which are capable of preventing coil coatings from peeling off due to the coils being brought into contact with each other.

A flange 15-1 having an inner wall surface 15-1a is provided to each end of the core 13. A cutout 17 is provided on the flange inner wall surface 15-1a in such a manner that one inner corner is cut out up to a certain depth as it is receding toward a flange side from a boundary between the flange inner wall surface 15-1a and the core 13.