A vector control apparatus that is configured to perform vector control by controlling a magnetic-excitation axis voltage (V dc *) and a torque axis voltage (V qc *) orthogonal to the magnetic-excitation axis (dc-axis) so that a magnetic-excitation axis component (I dc) and a torque axis component (I qc) of a motor current which flows in an alternating current motor become target values, comprising: an alternating voltage superimposing unit that is configured to superimpose an alternating voltage with a frequency that is different from a frequency of the motor current, to resolve the alternating voltage into a component of the magnetic-excitation axis voltage (V dc *) and a component of the torque axis voltage (V qc *); a high-frequency current phase-difference computing unit that, having a reference phase of the alternating voltage be a superimposing axis (p-axis), is configured to subtract a phase (θ pdc) of the superimposing axis (p-axis) from a phase (arctan(ΔIqc/ΔI dc)) of a high-frequency current that is generated in the motor current by the alternating voltage, and to compute thereby an axis-error reference amount (Xθ pd) that is based on a phase difference (θ ivh) between the high-frequency current and the alternating voltage; a superimposing axis adjusting unit that is configured to adjust a phase direction of the superimposing axis (p-axis) by a proportional integration of a deviation between the axis-error reference amount (Xθ pd) and a target value (Xθ pd0) so that the axis-error reference amount (Xθ qd) becomes zero or a predetermined target value; an axis deviation amount computing unit that is configured to compute an axis deviation amount (Δθ c) between the superimposing axis (p-axis) whose direction has been adjusted by the superimposing axis adjusting unit and the magnetic-excitation axis (dc-axis); and a magnetic-excitation axis adjusting unit that is configured to adjust a phase direction of the magnetic-excitation axis (dc-axis) by a proportional integration of a deviation between the axis deviation amount (Δθ c) and a target value (Δθ c0) so that the axis deviation amount (Δθ c) becomes zero or a predetermined target value. an alternating voltage superimposing unit that is configured to superimpose an alternating voltage with a frequency that is different from a frequency of the motor current, to resolve the alternating voltage into a component of the magnetic-excitation axis voltage (V dc *) and a component of the torque axis voltage (V qc *); a high-frequency current phase-difference computing unit that, having a reference phase of the alternating voltage be a superimposing axis (p-axis), is configured to subtract a phase (θ pdc) of the superimposing axis (p-axis) from a phase (arctan(ΔIqc/ΔI dc)) of a high-frequency current that is generated in the motor current by the alternating voltage, and to compute thereby an axis-error reference amount (Xθ pd) that is based on a phase difference (θ ivh) between the high-frequency current and the alternating voltage; a superimposing axis adjusting unit that is configured to adjust a phase direction of the superimposing axis (p-axis) by a proportional integration of a deviation between the axis-error reference amount (Xθ pd) and a target value (Xθ pd0) so that the axis-error reference amount (Xθ qd) becomes zero or a predetermined target value; an axis deviation amount computing unit that is configured to compute an axis deviation amount (Δθ c) between the superimposing axis (p-axis) whose direction has been adjusted by the superimposing axis adjusting unit and the magnetic-excitation axis (dc-axis); and a magnetic-excitation axis adjusting unit that is configured to adjust a phase direction of the magnetic-excitation axis (dc-axis) by a proportional integration of a deviation between the axis deviation amount (Δθ c) and a target value (Δθ c0) so that the axis deviation amount (Δθ c) becomes zero or a predetermined target value.