This study aims to explore professors’ job satisfaction and the factors that influence their satisfaction. Professors whose main duties were instruction, research, service, and advising (i.e., four types of responsibilities) were invited to participate in the study; the participants of the study ( n = 117) completed a questionnaire survey, and interviews ( n = 50) were also conducted to investigate their job perceptions. The study proposed a model that includes a second-order hierarchy of professors’ job satisfaction comprising four duties (i.e., instruction, research, service, and advising) and factors that influence job satisfaction. The results revealed that the participating professors tended to be moderately satisfied with their jobs and that the job satisfaction of full professors was greater than that of assistant professors. The order of four key duties that influenced professors’ overall job satisfaction were service, instruction, advising, and research. Furthermore, consistent with motivator-hygiene theory, the “university work environment” and the “nature of academic job” were the two factors that significantly influenced the job satisfaction of the participants. Of these two factors, the “university work environment” had a greater influence in predicting the participants’ job satisfaction, especially for higher-ranked professors. The study findings suggest that universities can increase the job satisfaction of professors by enhancing their professional development activities; improving their work environment, equipment, and support; providing more regulatory flexibility; and implementing teacher grievance mechanisms and reward systems that meet the needs of professors.