This study focused on the development of a metaverse-based rainforest ecosystem for high school students and tested its effectiveness in terms of students’ academic achievement and learning satisfaction. In this study, the metaverse platform ZEP is used to simulate a rainforest ecosystem. ZEP jointly developed by Supercat and Naver Z was formally launched in Korea on March 16, 2022. ZEP is a platform where users can integrate through avatars and integrates the metaverse’s virtual space map, video conferences, materials, movies and presentations displayed in object form. Ease of access, cost-effectiveness, interactivity, and user-friendliness are some of the strengths of the ZEP metaverse platform. The ZEP metaverse materials for high school biology were developed to serve as a hybrid world between the real and the virtual world. Data collection for the metaverse group was carried out using the pretest-posttest method, comparing it with two control groups—one using textbooks and the other using videos. The results indicate that the experimental group with metaverse technology is effective in improving students’ learning achievement and satisfaction. Therefore, it is proposed that the metaverse in education is valuable for teachers and learners because it could lead to student engagement and motivation in the classroom.