A method for using a film formation apparatus includes performing a main cleaning process and a post cleaning process in this order inside a reaction chamber. The main cleaning process is arranged to supply a cleaning gas containing fluorine into the reaction chamber while exhausting gas from inside the reaction chamber, thereby etching a film formation by-product containing silicon. The post cleaning process is arranged to remove a silicon-containing fluoride generated by the main cleaning process and remaining inside the reaction chamber and to alternately repeat, a plurality of times, supplying an oxidizing gas into the reaction chamber to transform the silicon-containing fluoride into an intermediate product by oxidization, and supplying hydrogen fluoride gas into the reaction chamber while exhausting gas from inside the reaction chamber to remove the intermediate product by a reaction between the hydrogen fluoride gas and the intermediate product.