Problem solving skills is one of six topical areas of physics education research, whereas the research about implementation of Project Based Learning-Science Technology Engineering and Mathematics (PjBL-STEM) to enhance students' problem solving skills is still lacking. This research purposed to reveal the impact of PjBL-STEM on students' problem solving skills in the topic of Electromagnetic Induction with a quasi experiment non-equivalent group design. Grade XII students of Senior High School 2 Pasuruan Indonesia were distributed to Experiment class (PjBL-STEM)(N= 36) and Comparison class (PjBL)(N= 38). Students worked on two projects, which were light shake and transformator. Problem Solving Skills Test with 0.681 Cronbach's alpha reliability was used as research instrument. Data analysis was done with t-test, effect size, and N-gain. The result showed PjBL-STEM gained problem solving skills significantly higher than the PjBL. Both classes had medium category in the skill's improvement. With" Very Large" effect size, the operationalization implementation of PjBL-STEM model had very large impact than PjBL class in increasing students' problem solving skills. The final questionnaire revealed students in both classes had positive response (Agree and Strongly Agree), which were quite similar towards the implementation of the learning model.