This study investigated elementary school students’ learning performances and behaviors in a maker education program. An informal after-school learning environment entitled Robot MakerSpace was created at a public elementary school in Taiwan and 30 grade 5 students voluntarily participated in a 16-week educational experiment. The student participants were randomly divided into two experimental groups. Students in the maker group received weekly educational robotics lessons, whereas those in the nonmaker group only engaged in other after-school learning activities such as homework practice in traditional classrooms. Mixed methods research was used for data collection. An experiment with a pretest–posttest and control group design was employed to measure the students’ electrical engineering and computer programming content knowledge and problem-solving skills. In addition, a qualitative approach with an emphasis on filed observation was adopted to evaluate the instructional implementation of the maker education program. The quantitative findings revealed that maker education training significantly improved the electrical engineering and computer programming content knowledge of the students and improved their problem-solving skills. The qualitative findings showed the students required considerable learning support from the instructor such as strategies for software and hardware debugging.