A fog spray machine, sometimes also called a fogger, is a type of equipment that applies a chemical solution in a fine spray. It is most often used for pest control as it helps to restrict the growth of mould and can also control the odours that it produces. It is also used as a popular tool for sanitizing surfaces.

The machine operates by creating a fine spray or mist which is applied to the areas that require disinfection. The spray density, via the size of the droplets, is controlled through a valve that the user adjusts by hand to provide required coverage. An average fogger machine can cover up to 12 square meters, or about enough to treat a large room. Its benefits are that it can reach corners and tight spaces and can penetrate porous surfaces. It should be used with care since the spray it produces can linger in the air for some time after application.