We evaluated the reflection and transmission characteristics of 7 types of glasses used as building materials at a frequency of 220-320 GHz. In case the incident angle is 0 degree, reflection characteristics is almost the same regardless of the types of the glasses. Transmission characteristics depends only on the thickness of glasses except for heat absorbing plate glass. We measured the dependence of reflection characteristics on the incident angle, and used it as a parameter of materials in the propagation simulation. The indoor propagation simulation results using the measured reflection characteristics of glasses indicates that the reflection at high incident angle in our model is larger than that of ITU-R model.