Media Didactica is a term used to express the use of media tools in teaching-learning processes. In other words, the subject of "educational-media competences" is the educational competences that empower teachers in teaching students and promoting media competences in them, and enable teachers to use media competences in the education of their students(Tolodzicki, Graf., 2019; Tied 2020) .The present study was conducted with the aim of explaining how to use educational media skills by high school teachers in Tehran and its consequences on students. The research method was a mixed exploratory type.The statistical population of the research was specialists in the fields related to media competencies and all teachers of high schools of education. From the group of experts, 15 experts were interviewed in a targeted way. With this number, the researcher reached theoretical saturation in collecting information in the interview stage. In the quantitative part, 185 teachers were studied by stratified and multi-stage sampling method to select teachers.

Descriptive and inferential statistics methods were used to analyze the data. In the descriptive statistics section; frequency and percentage, mean and standard deviation, and in the inferential statistics section, confirmatory factor analysis of the first and second order was used with the help of LISREL 8.7 software. tudied by stratified and multi-stage sampling method to select teachers.

In the process of action, first, using a semi-structured interview, the components of using mediaDidactica were identified and a researcher-made questionnaire was designed. In the next step, it was given to a group of experts to measure validity, and after confirming its validity, it was given to teachers to measure reliability. The results of the confirmatory factor analysis of the statistical fit of the model with the research data showed that the model included the three-factor model by placing 28 questions on the three factors of the theoretical model "lesson preparation", "lesson execution" and "evaluation".

In general, the results showed that teachers have media Didactica in three dimensions and its components are: teaching-learning process (use in lesson preparation, lesson implementation and lesson evaluation), promotion of competence (individual competence and job competence), social development (participation in school and participation at the organization level) are used.

Finally, the use of Media Didactica by teachers has had a significant predictive effect in explaining students' media literacy in terms of media use and media understanding.

Keywords: Media Didactica, lesson preparation, lesson implementation, evaluation.