Elevators appear in the Boss Rooms and starting rooms of every floor. It is a red box with a door and a light inside. In order to proceed to the next floor you must first defeat the floor's boss; this will spawn an Item near the Elevator on a pedestal and allow the Elevator to be used. Upon use of the Elevator after a Boss the player will be taken to another starting room on the next floor. This starting room will be completely empty except for the Elevator. Additionally, this Elevator no serves no purpose and cannot be used by the player.
in earlier versions, if you had the magnet, there was a chance that when on a new floor the rooms would appear in the map but no doors would be generated, making it impossible to get to the other rooms forcing you to end the run. (This bug still occurs, even without magnet)