An air conditioner support device for supporting an air conditioner in a window unit in a building, said air conditioner support device comprising a platform having a first half and a second half slidably connected via a connecting rod; a lip disposed on the first side of the first and second half of the platform; a first adjustable pivot arm and second adjustable pivot arm for supporting the platform in the window unit; wherein the platform is for placing in the window unit over a window sill and below a window wherein the air conditioner can be placed atop the platform.