De or het stafafdeling?

The correct Dutch article is:

de stafafdeling

Rule Words ending in -ing: almost always de. See the rule

How to use stafafdeling

the stafafdelingde stafafdeling
this stafafdelingdeze stafafdeling
that stafafdelingdie stafafdeling
our stafafdelingonze stafafdeling
your stafafdelingjouw stafafdeling
every stafafdelingelke stafafdeling
which stafafdeling?welke stafafdeling?
a big stafafdeling / the big stafafdelingeen grote stafafdeling, de grote stafafdeling