The purpose of this study is to investigate the opinions of teachers, directors, and parents about childcare teachers' facial expression language. We performed in-depth interviews based on literature and previous studies, which consisted of ten childcare teachers, ten directors, and ten parents. From the in-depth interviews, we are able to mainly conclude that all groups think that a childcare teacher's facial expression language is very important, and strongly influences interpersonal problems and work performance. Mostly, childcare teachers aim to have pleasant facial expressions. However they complain that in some situations it is difficult to do so, which causes severe stress. They argued that the facial expressions of both the director of the childcare center and the parents are also very important for children. However, the directors thought that teachers' facial expressions affect children and their parents' impressions of the teachers and quality of childcare. The parents are usually highly satisfied with the childcare when the teacher has a pleasant facial expression, which motivates the parents to have a positive impression of the teacher. Taken together, childcare teachers' facial expression language is critical for children and the childcare environment. Thus, developing an education program for facial expression language would be helpful for improving the quality of child care. Plus, childcare environments should be developed so that teachers do not experience difficulty in having pleasant facial expressions. This result might have the limitation of being collected from only female childcare teachers, directors, and parents.