Provided is a radial direction controller capable of handling changes in negative bearing stiffness according to the mounting orientation. This radial direction controller, which is a magnetic bearing device that lifts and supports a rotating body by electromagnets, is equipped with: a radial control circuit for controlling displacement of the axis of the rotating body in the radial direction; a negative bearing stiffness elimination circuit that is connected in parallel with the radial control circuit and outputs a signal about the negative bearing stiffness; converters that output current values for controlling the electromagnets, based on the output signals from these circuits; filters that extract the DC component from the current values; computing units that compute correction coefficients based on the extracted DC components and the bias current of the electromagnets; and multiplication units that multiply the computed correction coefficients with the signal output from the negative bearing stiffness elimination circuit.