The Ego Depletion phenomenon is a real phenomenon that can be used to motivate auditors. In addition, the audit of financial statements provides useful conditions for the study of Depletion, and therefore, the various tasks that auditors perform (including judgment and providing opinions), lead to the study of this phenomenon. The upcoming research, in terms of its purpose, is applied and of a descriptive correlational type, based on the structural equation model. The data of this research were collected through the distribution of questionnaires among 360 auditors working in Mashhad audit institutes who were selected by a Sample method available. Among these, 340 questionnaires were received and used as the basis for statistical analysis. Structural equation method with the help of SmartPLS software was used for data analysis. The results show that Ego Depletion has a significant negative effect on auditors' judgment. Cognitive fatigue moderates the relationship between Ego Depletion and auditors' judgment. Considering that cognitive fatigue is a psychological state that occurs as a result of long-term cognitive activity, the results of the upcoming study can be effective when auditors make judgments, especially in times of exhaustion and fatigue, and overshadows the sensitivity of possible mistakes in judgment. This study has increased the existing theoretical literature in terms of examining the effect of the auditor's Ego Depletion on his judgment, and also by examining the effect of cognitive fatigue on the relationship between Ego Depletion and auditors' judgment, it contributes to increasing the existing knowledge in this field.