The purpose of this study is to identify the structural relationship between teacher collaboration, job stress, teacher efficacy, and job satisfaction, and to test model differences between elementary and middle school. To this end, among the survey response data of 6,138 Korean teachers (3,207 elementary school teachers, 2,931 middle school teachers) who participated in TALIS 2018, 6,072 data excluding missing values were finally analyzed using the structural equation model. The bootstrapping method was implemented to verify the significance of mediating effects between variables, and multigroup analysis was performed to verify the model difference between elementary and middle schools. The results are as follows. First, the relationship between teacher collaboration, job stress, teacher efficacy, and job satisfaction showed consistent results with hypotheses based on previous researches, excluding the relationship between job stress and teacher efficacy. Second, both the mediating effects of job stress and teacher efficacy on the relationship between teacher collaboration and job satisfaction were statistically significant. Third, in both elementary and middle schools, the path of teacher collaboration towards teacher efficacy and job satisfaction and the path of teacher efficacy towards job satisfaction were positively significant. However, the path from teacher collaboration to job stress and the path from job stress to job satisfaction were negatively significant. Especially, the effect of teacher collaboration on teacher efficacy was greater in elementary school than in middle school and statistically significant. Fourth, there was no statistically significant difference in the single-mediated effects of job stress and teacher efficacy in the relationship between teacher collaboration and job satisfaction in both the elementary and middle school groups. Based on these results, implications for increasing teacher job satisfaction were presented.