This research aims were to: (1) produce a PhET simulation-based learning device that who being used in physics learning activities by using Problem Based Learning (PBL) model to improve critical thinking skills of students MAN 3 Sleman in chapter work and energy, (2) knowing the effectiveness of learning medium in the form of PhET simulation in physics learning activity using PBL model, and (3) knowing the improvement of critical thinking skills of students in MAN 3 Sleman. This research is a development research with 4D model. The define stage, defines the problem. The design stage, developing physics-based learning device PhET simulation using PBL model. The development stage, resulting in PhET simulation based physics learning device using the revised PBL model. The disseminate stage, the dissemination of PhET simulation based physics learning device using PBL model. The research results, (1) The PhET simulation based physics learning device using PBL model feasible use in physics learning activity. This is evidenced from the acquisition of Aiken's V validity score through validation result, students's response result, and valid and reliable assessor approval level, (2) Learning medium in the form of PhET simulation is effectively used in physics learning activities. This is evidenced by the sig value. of 0.00 in the modeling class and implementation class, meaning the PhET simulation application allows students to improve their critical thinking skills, and (3) Improvement of critical thinking skills of students MAN 3 Sleman in modeling class and implementation class that are 23.84% and 41.90% respectively with value of standard gain of 0.35 and 0.61 which are included in medium category.