the present invention has been made in an effort to provide a cvd apparatus and a method of manufacturing a semiconductor device using the same having advantages of providing a precursor supplying apparatus that can prevent defects and / or contamination by source material - based contaminants that may result from certain operations performed during maintenance work . an exemplary precursor supplying apparatus for a cvd apparatus according to an embodiment of the present invention includes a precursor storage tank , a gas inlet line adapted to flow inert gas into the storage tank , a gas supply line connected to the storage tank and adapted to supply a precursor to a cvd chamber , and a backflow - prevention line connected to the gas inlet line and adapted to flow an inert gas into the storage tank and / or the gas inlet line .