The décor and furniture of the Bedroom reflect the personality of Prince Józef Poniatowski, owner of Myślewice. In the interior hangs a portrait of him shown in the uniform of the Marshal of France with the Star of the Legion of Honour and Star of the Order of Virtuti Military (made by Josef Grassi), as well as a painting depicting the Death of Prince Józef Poniatowski in the Depths of the Weisse Elster River, painted in 1820 by Marcin Zaleski (1796–1877), based on an etching by Philibert-Louis Debucourt. Noon light shines on the marble bust of Napoleon Bonaparte sculpted by Joseph Chinard, made in c. 1810. The whole is complemented with a lithography depicting Prince Józef Poniatowski.

The furnishing of the room comprises an Empire-style mahogany bed and a small cabinet (early 19th century), as well as a fireplace screen adorned with 18th-century fabric, an overbed table with adjustable height, a small commode, and three chairs inlaid with ivory. On the card table stands a mahogany casket decorated with a plaque, on which the names of distinguished Poles have been engraved: Kościuszko, Niemcewicz, and Kniaziewicz – soldiers who fought on the side of Napoleon Bonaparte. On the mantelpiece of the sandstone fireplace is a marble bust of Flora (1784), signed by Jean-Baptiste Watelet, and, on the side of it, two amphoras made of dark marble are worth noting. In the Bedroom, visitors will also see a painting of Madonna with Child by Giovanni Battista Salvi, who was known as Sassoferrato, and two landscapes depicting shepherds.