Glass does not form any specific crystal when it changes state from liquid to solid. For this reason, the solid state of glass is represented in various terms at science education books. For example, 'amorphous solid', 'glassy state', 'super-cooled liquid' and 'highly viscous liquid' represent the solid state of glass. Among these expressions, the inclusion of the term 'liquid' often leads to the misconception that ‘the glass flows over a long period of time’. The Elementary School Science Teacher Guide (2009 revision) explains that the glass flows over a long period of time citing a medieval cathedral glass. It might be a significant educational issue in the point that 'Glass is no longer flowing when it is solidified once.' and the case of medieval cathedral glass is already pointed out in the scientific community as a false example. In this study, it was tried to investigate similar cases in textbooks and guidebooks of elementary, middle and high schools. Furthermore, it was tried in general chemistry books of university lectures. In addition, it was looked at how to guide 'glass' on internet major sites. The main results are as follows. First, in the science field of elementary, it was began to explain that ‘The state of the glass is able to reform.’ from the 2007 revision guidebook of the teachers. The 2009 Revised Teacher's Guidebook explains that the glass flows over a long period of time mentioning the case of medieval cathedral glass. Second, in the science field of middle school, there were differences in the explanation of glass according to time period. Anyway, in a science textbook first published in 2001 (Black Box Publication), it was found a similar explanation introducing glass as a liquid. Third, in the high school textbook, glass was clearly expressed as 'amorphous solid' regardless of the time period. Fourth, in general chemistry textbooks, it was expressed that 'glass is an amorphous solid' or 'glass has liquid properties' ambiguously. Fifth, in the case of Internet search, information about glass was slightly different in each site. And the information was relatively difficult for the students and the general public to understand the state of glass accurately. Based on the above results, some educational issues were discussed.