The building has a rectangular perimeter of about 40 x 70 meters. Its ground-plan is symmetric to its central pivot and it contains to atria. Its ground-floor has been modeled to house shops. There is a staircase of monumental style that connects the parterre up to the first floor. Two towers on the edges and the central part of the facade (formed by a propylon of Toscanic and Ionian style and the pediment) distinguish as they jut out. Particularly remarkable is the rich painted decorations in the interior.

The building was constructed between 1876 and 1891 based on Hernest Ziller's studies. The problems that appear during its construction, brought about several alterations to the original plans, which were still carried out by Ziller himself who managed to give the Townhall a distinct form.

The construction was financed by the state and the city and its completion and inauguration took place thanks to the persistence and the fervor of the then Mayor D. Vafiadakis, who passed away in 1898.

Restoration interventions have been applied in part of the building and most specifically in the interior spaces (colors faithful to the authentic ones, floor restorations, conservation and restoration works on the doors and windows frames, parts of the roof, insulation of rooms and roofs, etc.). Restoration of the facets is scheduled to follow.

Today, the building houses offices of the Municipality of Ermoupolis, Courts and other public services.

By a ministerial decree of 1980, it has been identified as a work of art.