The purpose of this study was to develop a Digital Book using the principles of Universal Design for Learning (UDL) so that teenage students with developmental disabilities that exhibit diverse literacy levels can participate in reading activities per their skills and interests. The study was conducted in three parts: design, development, and evaluation. First, in designing the study, an analysis of demand for Digital Books and literature reviews of research into Digital Book user interfaces and application of UDL principles were conducted. Second, in the development stage of the study, a prototype of the Digital Book was conceived through collaboration with a programmer. The prototype was reviewed by an expert consultant and revised to develop the final Digital Book. Third, in the evaluation stage, an advisory group of 25 special education specialists or reading specialists evaluated the user experience. In reviewing the field application, the Book was distributed to 30 students of the special education teachers within the advisory group. The students were observed for their reading activity and interviewed afterwards. Lastly, the significance of the study is determined and the implications for future studies on developing UDL-based Digital Books are proposed.