Ac motor control device

This AC motor control device comprises: an inverter including switching elements; a switching control means that controls the switching elements; and a phase detecting means that detects the rotor phase of the AC motor, wherein the switching control means controls the switching elements such that the voltage waveform of the inverter has half-wave symmetry in a section, in the width of ±180 degrees, with the fundamental wave voltage phase of 180 degrees as a center, the switching control means controls the switching elements such that the higher harmonic voltage phase of the inverter is variable on the basis of a fundamental wave voltage/rotor phase difference, which is a difference between the fundamental voltage phase and the rotor phase of the AC motor, and the switching control means controls the switching elements such that the higher harmonic voltage amplitude of the inverter is inversely proportional to the order of the higher harmonic voltage amplitude.