Basically, the evacuated chamber is to perform some experiments. The spacecraft is of single stage to orbit variety. I am asking in terms of whether one can build it using generally used materials of construction like iron, etc.
Edit 1: The space for the vacuum chamber would be about 40 % of the space craft's volume, somewhat like an airship. the spacecraft should be able to evacuate the chamber on its own, even if it is on the surface of the earth, or any other planet with a dense atmosphere. It would probably be used to transfer stuff which would be air-sensitive, like alien bodies which were unaccustomed to oxygen gas.
Edit 2: The technological development of my species is the same as that of humans. An airlock big enough to contain many small space vehicles (in SF) (like an aircraft carrier carries planes) would be sufficient for my needs.
Edit 3: Vacuuum as in vacuum wikipedia 10−13 torr (13 pPa)