To provide a glass sash structure without requiring a curtain.

This glass sash structure is formed of a main frame and a storing seat part. A sealing space is formed in the main frame, two glass panes apart from each other at a proper distance are installed in the space, and a water access port is provided at a bottom end part. A storage tank having a pump and a water storage tank installed therein is installed on the storing seat part, the pump receives a proper control to raise water from the water storage tank, and fills water from the water access port between the sealing space. Also, water is extracted from the sealing space, returned from the water access port to the water storage tank, and forms one water supply and water storage system. By combining the color of the liquid with proper water supply and water storage to the sealing space of the glass panes, such transparent effects of curtains as the complete, semi-, or non-cutout of light beam can be provided.