In this study, I made an analysis of gender stereotype used as psychological mechanism, concerning the discharge of married women employees in Nonghyup(Korean Agricultural Cooperatives), for which they worked together with their male spouses. The stereotype on a married woman clerk is presented to the employers, the co-workers, and the family in various ways, and they allow or punish her according to their own stereotype. I tried to show that when this stereotypical system of allowance and punishment results in an illegal act of gender discrimination, all the employees are psychologically forced to acknowledge that sort of act. First of all, with a help of selective inattention to women employees with low-income and low-status, and of some statistical means, the employers activated the stereotype on married woman. Then familism of whole Korean society, which is based on kin-oriented, Confucian relationships, operated the stereotypical system of allowance and punishment, making other employees consent to the employer's decision. Besides discharged women faced the psychological demands for domestic role in their family. Thus, it was the three axes of the employers, the employees, and the discharged that activated the operation of stereotype in this discharge case. Nonghyup case is considerable, because it was an illegal act depended not on physical violence or pressure, but on psychological mechanism like gender stereotype. When gender discrimination in labor market was caused by deep-rooted social stereotype, it is justified in general by forcing the whole society to consent to. The analysis above tells us the need for feminist psychology, not only to expose the correlation between gender stereotype and discriminative act, but also to show the adherent gender stereotype and to search for the possibility of its change.