The Anteroom is the second room Luigi explores in Luigi's Mansion; it is located in the first area. The Anteroom resembles a short hallway and is where Luigi first encounters Purple Punchers.
Coming from the Parlor, upon entry, the doors were blocked with force fields, trapping the green plumber he was attacked by several Gold Ghosts. After dispatching these ghouls Luigi was attacked by some Purple Punchers, who proved to be much more powerful than there weaker cousins. Still the brave plumber managed to dispatch them. When all the ghosts were captured, the force fields disappeared and Luigi continued his adventure into the Wardrobe Room.
The Anteroom is probably the blandest room in the game having nothing but vases on tables in it.