Introduction: Professional skepticism is an important and effective element on auditors' judgment and overshadows audit quality. Therefore, the main goal of the current research is to predict the auditor's professional skepticism based on the ethical climate of the organization and demographic characteristics such as gender, education and experience. Material and Methods: The research method in this research is descriptive-correlation research. The statistical population includes auditors working in the auditing profession and the statistical sample of the present study is auditors working in auditing institutions. Sampling method, sampling is available. About 70% of the sample are men and the rest are women. The instrument for measuring research variables is a standard questionnaire. The reliability of the questionnaire is determined based on Cronbach's alpha. Multivariate regression test using SPSS software was used to analyze the collected data. Results: The results of the research confirm the positive and significant relationship between the ethical climate and the auditor's professional skepticism. In other words, the growth of the moral atmosphere leads to the improvement of the professional skepticism of auditors. Also, the results showed that gender, level of education and experience have no significant relationship on the professional skepticism of auditors. Conclusion: The moral atmosphere of the organization is an important factor in the exercise of professional skepticism. Therefore, the development of ethical atmosphere in audit firms can improve audit quality.
