This paper shows typical functions required on electronic textbooks to be adopted in various countries, trial implementation of these functions, and their verification of representation and behavior in six e-book platforms. First, the authors extracted the functions by checking preceding researches and investigations. The result contains 52 items, including 7 categories of “authentication”, “copyright”, “contents representation”, “related information”, “additional information by learners”, “learning support”, and “restriction of contents and platforms”. Next, these functions were implemented with ePub3 format e-books. ePub3 is going to be one of de jure standard format of e-books. Also, contents representation and behavior of the result ePub e-books were verified on 6 types of e-book platforms on operating systems of iOS, Android, Windows, and Kindle Linux. The verification result shows that iBooks3 on iOS worked best among the 6 e-book readers. Also it shows that many e-book readers support only representation of ePub2 files, while HTML5, JavaScript, and Web API are not supported yet.
