The purpose of this study is to improve the average torque and reduce the torque ripple by optimizing the design of the IPM motor to be compared using the Taguchi method, which is a quality engineering method. First, the parameters of the entire motor were optimized using the average torque as the evaluation value. Next, the details of the motor are optimized by considering the torque ripple. In the optimal design for improving the average torque, the average torque was improved by increasing the number of turns and increasing the slot area without reducing the magnetic flux. In the optimal design for reducing torque ripple, the stator teeth were made close to the closed slot and the gap length was increased by shortening the tooth edge.