Recently, demands for difficult-to-cut materials with high mechanical properties have been increased in various industrial fields, such as the aerospace and automobile industries. Because difficult-to-cut materials have high mechanical properties, it is difficult to achieve conventional machining. Therefore, many researchers have been studying the machining methods for difficult-to-cut materials. One of the many studies of how to cut difficult-to-cut materials involves plasma-assisted machining (PAM) is a machining method that softens difficult-to-cut materials by a plasma heat source to remove by the cutting tool. PAM has various machining conditions, and it is very important to determine the optimal conditions to improve machining accuracy and efficiency. In this study, the cutting force was analyzed by using a gas flow rate and power which are the easiest to control in the PAM system. The results of this study can be applied to PAM data under optimum conditions.