A control device for an AC rotary machine, which controls an AC rotary machine in which a rotor is rotated by a rotating magnetic field formed by a multi-phase alternating current flowing through an armature winding of a stator, the control device comprising: an inverter that applies a voltage to the armature winding of the AC rotary machine; an inverter connection unit that connects the armature winding to the inverter; a magnetic field generator that generates an angle detecting magnetic field for detecting a rotation angle of the AC rotary machine by rotating in synchronization with the rotor; an angle detector that detects two mutually orthogonal components of the angle detecting magnetic field generated by the magnetic field generator as a sine signal and a cosine signal; and a control calculation unit that controls a voltage applied to the inverter on the basis of a current command of the AC rotary machine and angle information obtained from the sine signal and the cosine signal, wherein the control calculation unit includes an angle correction calculation unit that corrects an error in the angle information caused by a noise magnetic field generated by a multi-phase alternating current flowing through the inverter connection unit by using a correction signal having a phase and an amplitude that are determined in accordance with a current vector of the multi-phase alternating current flowing through the inverter connection unit and a phase correction constant and an amplitude correction constant determined from a relative positional relationship between the inverter connection unit and the angle detector, and outputs the corrected error as a corrected electrical angle, and the control calculation unit controls the inverter on the basis of the corrected electrical angle. an inverter that applies a voltage to the armature winding of the AC rotary machine; an inverter connection unit that connects the armature winding to the inverter; a magnetic field generator that generates an angle detecting magnetic field for detecting a rotation angle of the AC rotary machine by rotating in synchronization with the rotor; an angle detector that detects two mutually orthogonal components of the angle detecting magnetic field generated by the magnetic field generator as a sine signal and a cosine signal; and a control calculation unit that controls a voltage applied to the inverter on the basis of a current command of the AC rotary machine and angle information obtained from the sine signal and the cosine signal, wherein the control calculation unit includes an angle correction calculation unit that corrects an error in the angle information caused by a noise magnetic field generated by a multi-phase alternating current flowing through the inverter connection unit by using a correction signal having a phase and an amplitude that are determined in accordance with a current vector of the multi-phase alternating current flowing through the inverter connection unit and a phase correction constant and an amplitude correction constant determined from a relative positional relationship between the inverter connection unit and the angle detector, and outputs the corrected error as a corrected electrical angle, and the control calculation unit controls the inverter on the basis of the corrected electrical angle.