There is still a lack of a universally applicable STEAM teaching methodology for students older than 15 in various countries. The project brings together an international team to prepare STEAM methodology in parallel with ecological literacy in formal and non-formal education, developing three long-term intellectual products: the teaching concept (IO1), teaching materials (IO2) and the practical guide (IO3). They are designed to increase the motivation, knowledge and skills of EcoSTEAM learning.