This article presents and discusses an innovative pedagogical device designed for training pre-service teachers on the nature of science. We endorse an approach according to which aspects of the nature of science should be explicitly discussed in order to be understood by learners. We identified quantum physics, and more precisely the principles of uncertainty and complementarity, as a rich topic suitable for such a discussion. Our training device consists in preparing and staging a new type of theater, the “scientific experimental theater,” based both on the characteristics of Brecht’s theater and Kelly’ cyclic theory of learning. This device was implemented with a group of eight pre-service teachers. According to our observations, the approach favors their involvement and provides them with a frame for expressing their doubts and confronting their points of view. By analyzing their discussion, we identified several aspects of the nature of science that the pre-service teachers raised spontaneously: subjectivity, the social and cultural embeddedness of science, the construction and status of models and the role of questioning in the development of science. The implemented device therefore appears as an interesting means for stimulating a rich discussion on the nature of science. This study opens new avenues for teachers’ and students’ training devices aimed at developing a critical and reflective stance on science.