The author of the interior constructed in the Neo-Baroque style is the Fellner & Helmer company from Vienna, one of the best companies in the world at the time. The exterior of the building in the Art Nouveau style was designed by architects Jan Kříženecký and Emil Králík.

The building of the theatre is decorated with ceramic masks symbolizing individual types of theatrical art, wreaths, a sculpture of Thalia, the goddess of theatre, with the slogan “Art - the Power of Life”. The most precious part of the decoration comprises the sculptural group by sculptor Jan Štursa, and the curtain by Theodor Hilšer, celebrating art in the Mladá Boleslav region.