During a mobility program for teachers (Erasmus KA1) to develop CLIL (Content and Language Integrated Learning) skills in June 2017, two teachers from Hustopece High School in the Czech Republic and a teacher from Le Mans High School in France attended met. Many common points emerged: our schools are of a comparable size, have a youth audience from the rural world, begin to develop CLIL lessons to a public of young scientists to convince ... and have a culture common sharing, opening to the outside. From this formation germinated the idea of exchanging on our teaching practices CLIL nascent.