Endoscopic sinus surgery (ESS) has been performed with a navigation system to reduce a risk of causing injuries and complications during the surgery. However, supporting the improvement of surgeons’ skill levels is important to further improve the safety of ESS. We previously developed a method for analyzing and evaluating the motion of the forceps during a glioma surgery and a laparoscopic cholecystectomy in order to help surgeons to learn surgical skills. As a surgeon need to operate an endoscopic camera and a forceps in the case of ESS, we focused on analyzing a camera operation. Therefore, in this study, we present a quantitative analysis method of a camera operation during ESS. By using the information obtained by a navigation system, we developed a method for quantifying a camera operation with five analytical parameters and estimating surgeons' skill levels based on discrimination analysis. For fundamental validation, we analyzed a camera operation during a simulated bone resection task for ESS using a nasal bone phantom. Eight surgeons (four experts and four novices) participated to the study and the task was performed five times by each surgeon. A total of forty procedures were analyzed to validate our method. Based on the validation results, we believe that our analytical method is effective for quantitatively analyzing and evaluating surgical performances without depending on years of experience.