We classified 258 public astronomical observatories into three forms. In this research, we investigated the observation room features of the public Astronomical Observatory. As a result, the following findings were revealed. ① Independent type : Many in the urbanization Control Areas, the telescope’s aperture is small. Movable roof are mostly double-opening type. ② Simultaneous type : Functions other than the observation room are diversified. Movable roof are mostly single open type. ③ Combined type : The diameter of the telescope is large. Movable roof are mostly upper and lower type. Questionnaire survey revealed problems and ideas by form.