The challenge for a teacher in the learning process is to engage students with the subject and help them comprehend biology using creative and efficient learning media. The research aims to provide information on the postharvest fungi as well as their role as contaminant fungi in Bantenese emping melinjo chips as the contents in the poster as learning media and to determine its effect on assisting student knowledge and critical thinking skills. The Research and Development was conducted using the ADDIE model. The information was gathered through the use of interview guidelines, validation sheets, and students' response questionnaires. The research findings informed that a total of 35 species of post harvest fungi have been successfully isolated from eight different locations in Banten Province. The evaluation results of the poster as learning media showed that it was considered very valid by media and material validators. Student responses showed that the developed poster was categorized as very feasible media. The student knowledge and critical thinking skills achievement facilitated by the poster as e-learning media was significantly higher compared to another class. The produced poster was found to be suitable to be used as e-learning media in the Biology subject.