This study was conducted to investigate the effect and causal relationship between job competency and the chef's competency on job performance on cooks who work for restaurants and the chef's leadership. Currently, an online survey was conducted on cooks of restaurants in the Seoul metropolitan area, and the reliability and validity of the research model were analyzed and verified by analyzing 386 effective data. In future studies, it is necessary to conduct research using various variables. Using SPSS 22.0, the collected data are first used to identify the general characteristics of the sample. Finally, the hypothesis of the study was verified through multiple regression analysis. As a result of verifying the research hypothesis, Hypothesis 1 was adopted, and it was found that transformational leadership, transactional leadership, and servant leadership had a significant positive effect on job performance. Without a sense of consideration as a colleague working with the chef for short-term performance, there is a limit to the role and necessity of not having leadership in the absence of difference from the chefs due to the skill acquisition and knowledge improvement through various media. The chef also needs to prioritize communication and agreement through leadership to achieve employees' job competencies and job performance. As a limitation of this study, the survey was limited to restaurant companies in the Seoul metropolitan area, and variables were used as variables to examine the influence of chef's leadership on chef's job performance and the relationship of chef's job performance.