This study aims to evaluate the practicality, validity, and effectiveness of the static electricity subject matter learning tool for junior high school students. Learning tools include syllabus, lesson plans, teaching materials, student worksheet, and assessment sheets. The research model used is the Tessmer development model which consists of five steps, namely as follows: 1) self-evaluation; 2) expert opinion (expert review); 3) Individual trial (one to one); 4) small group trials; and 5) field test. The data analysis technique used in this research is quantitative analysis which includes data analysis on the validity of learning tools, data analysis on the practicality of learning tools, and data analysis on the effectiveness of learning tools. This type of research is development research. The research was conducted at SMP Negeri 2 Bati-Bati. The research subjects consisted of the subject of validation of five experts, the subject of individual trials of three students, the small group trial consisting of five students and the field test consisting of 27 students. The results showed that the learning tools developed were valid, practical and effective. Valid based on the results of tool validation by the validator including syllabus, lesson plans, teaching materials, worksheets, and LKPD assessment sheets which are categorized as valid and readability test of teaching materials and worksheets by students who are categorized as good. Practical based on the activities of teachers and students who are categorized as good from the lesson plan implementation sheet. Effective based on the results of worksheets that show an increasing trend in indicators adapted from Watson-Glaser's critical thinking skills.