It is important for students to experience STEM education for countries to be able to increase their scientific research capacity and economic progress. The purpose of this research was to determine the effect of problem based STEM education on the perception of middle-school 5th grade students of engineering, engineers and technology. In the research, the single group pre-test and post-test experimental design which is one of the quantitative research methods was used. The study group of the research was consisted of 17 fifth grade students who were receiving education at a state school in the Akhisar district of the city of Manisa in the fall semester of the 2017-2018 academic year. The data of the research were collected with the What is Engineering? and What is Technology? surveys and Draw an Engineer Test. In the analysis of data, non-parametric tests, frequency and percentage analysis and descriptive analysis were used. Following the applications carried out in the research, it was determined that the perceptions of the students of engineering, engineers and technology were developed in the positive manner. In the pre-drawings of engineers, it was seen that the students mostly depicted repairmen or construction workers, whereas they gave place to engineering who produced and did design work in their post-drawings. In addition, it was seen that the perception of male engineers in the pre-drawings decreased in the post-drawings and that the perception of female engineers increased. It was determined that problem based STEM education was effective in terms of the students understanding that only electronical devices are not technology. In the light of the obtained results, suggestions were made about the effective use of problem based learning in the application of STEM education.