It is proved that for arbitrary
locally compact groups G the automorphism group Aut(G) is a complete
topological group. Several conditions equivalent to closedness of the group
Int(G) of inner automorphisms are given, such as G admits no nontrivial
central sequences. It is shown that Aut(G) is topologically embedded in
the automorphism group Autℛ(G) of the group von Neumann algebra.
However, closedness of Intℛ(G) does not imply closedness of Int(G), nor
conversely.