The diploma thesis focuses on learning Maths through French language using the CLIL method at a secondary vocational school. The acronym CLIL (Content and Language Integrated Learning), EMILE (Enseignement de Matières par Intégration d'une Langue Etrangère) or e.g. AICL (Apprentissage Intégré d'un Contenu et d'une Langue) refers to integrated learning of a content-based subject through an additional language. There are always two aims of such tuition. The first aim is the content goal (e.g. to gain particular specialized knowledge or skill in mathematics); the second aim is the language goal (e.g. to learn essential vocabulary and sentence structures in order to lead a discussion concerning the solution of a quadratic equation in the French language). Based on a literary research, analysis of educational CLIL materials, and especially in connection with theoretical grounds of the method (constructivism, problem-solving, critical thinking, active and communicative approach) there was established a study plan focusing on the topic of quadratic equations. The experimental tuition was put into practice with the 1st year students of a secondary school, where the French language is taught as the second foreign language. The main objective, apart from the tuition itself and its analysis, was to assess the...