Can you apply subsurf modifier to only some faces?

Quick question here; title pretty much says it all. Part of my mesh is set to smooth, but there aren’t enough faces there for it to look actually smooth. Can I put a subsurf modifier on only those faces?

The subsurf modifier has to affects the whole object.


Thanks for the answer. Oh well; I’ll find another way to make it work.

Not exactly.
You can, however, keep some faces from being smooth, even though they will be subsurfed. Simply select the faces and press “shift-e” then move the mouse until the edge is as sharp as you want it ;).