STEM integrated education is a modern, global education model that aims to develop high-level human resources in the 21st century. STEM integrated education is in line with the current Vietnamese educational development. Today, the focus is on developing students' abilities and qualities, especially the problem solving and creativity - one of the common competencies that all subjects and educational activities must aim for in the 2018 educational program. Integrated STEM teaching topic (hereinafter referred to as iSTEM) is one of three forms of STEM integrated education organization [1], widely implemented for all types of students in Viet Nam. The iSTEM topic follows an integrated internal, multi-disciplinary or interdisciplinary approach, the content closely following the current general education curriculum. In this article, we apply the research results published in previous articles [2, 3], on criteria and process for building iSTEM topics, building level 3 iSTEM topics and teaching the subject in the framework of pedagogical experimentation. Research methods: document research, model proposal, model operation, pedagogical experiment. Achievements: Level 3 iSTEM teaching topic document "Automatic hand washing machine to prevent Covid 19."