What kind of CEO is a great CEO? Compared to prior studies to answer this question on performance-based perspective, this study try to figure out the proper characteristics of CEO based on firms' fraud behavior combining the sense of morality in the perspective of upper echelon theory. To be specific, we want to clarify the negative relationship between CEO humility and firm's accounting fraud. In this study we define the characteristics of humility with 1) developmental orientation, 2) self-awareness, 3) appreciation of others, 4) low self-focus, 5) internal locus of control. Bringing Fraud Triangle theory which explain the antecedents of firm's accounting fraud, this study investigates how the five characteristics of humility affect firm's accounting fraud behavior. We predicted the more humble a CEO of a firm is, the less likelihood of accounting fraud of the firm would exist, and also the control function of the firm's governance related to the independence and effectiveness of board would mediate the relationship between CEO humility and accounting fraud. According to the logistic regression analysis, the prediction is supported. CEO humility is negatively related to the likelihood of accounting fraud. Also, it is shown that the separation of CEO and board chairmanship mediates the relationship between CEO humility and accounting fraud. That is, a more humble CEO is more likely to increase the control of corporate governance structure by having a separate person for chairman of board of directors and such governance structure leads to a lower likelihood of accounting fraud. These results suggest that a humble CEO can objectively and fairly evaluate his/her own performance and exhibits characteristics that contrast with those of a narcissist who prefers to exaggerate performance to generate attention and praise.