The founder of the spa is considered to be Jozef Szalay, who took over Szczawnica from his father in 1839 and erected the first spa buildings. In 1876, he donated the spa to the Krakow Academy of Arts and Sciences, which was bought by Count Adam Stadnicki in 1909. In the 1930s, interest in Szczawnica increased. Adam Stadnicki travelled to European resorts where he learned about modern healing techniques. On his return, he expanded and modernised the spa. Between 1934 and 1936, on the site of one of Poland's oldest spa houses, ‘Zamek’, he built a modern inhalatorium designed by Stanisław Dziewolski, the owner of Krościenko nad Dunajcem. It has installed state-of-the-art equipment, including inhalation devices from the Berlin-based company ‘Inhabad’ and the first pneumatic (pressure) chambers in Poland to support the treatment of bronchial asthma and emphysema. The furniture was brought from the ‘Jarnuszkiewicz and Co.’ workshop in Warsaw and the carpenter's shop in Nawojowa. The water supply installation was made by the ‘Kumer and Torba’ company from Rabka. During World War II, the sanatorium's attic housed a secret weapons and ammunition depot. The building luckily escaped the destruction that the Germans were preparing for it, and at the end of the war, the sanatorium staff managed to hide valuable equipment there. The sanatorium was nationalised in 1948 and re-privatised in 2005. Today, it belongs to the ‘Uzdrowisko Szczawnica’ enterprise. It is a stately modernist building with a white façade, surrounded by park-like larches and magnolias. A plaque commemorating Adam Stadnicki was erected in the building's main hall.

Currently, the ‘Inhalatorium’ Sanatorium in Szczawnica treats bronchial asthma, a variety of diseases of the upper and lower respiratory tract, musculoskeletal diseases, and rheumatic diseases. 
Also available are: balneological, physical therapy, hydrotherapy, kinesitherapy, light therapy, drug inhalation treatments.