The aims of this study are analyzing the relationship among internal marketing dimensions, internal customer satisfaction, organizational commitment, and customer orientation. Furthermore, we conducted a multi-group analysis to find out the effects of gender and position. The research model was validated by the basic statistics and PLS-SEM(structural equation modeling) using survey data collected in 3,303 samples from a large chemical company in Korea. The empirical results are as follows. First, internal marketing factors of a chemical company affect a significant impact on internal customer satisfaction, organizational commitment and customer orientation. The overall 68.89 percent of the dependent variables were explained. Second, the magnitude of the impact were ordered by “Management Support> Education and Training> Compensation System> Communication> Empowerment” to all groups. Third, according to a multi-group analysis, the magnitude of the impact of internal marketing factors on internal customers’ satisfaction varied from the gender (male, female) and the position (manager group, working group).