Abstract: An air filter for use with wood or coal stoves of the type having a plenum surrounding the firebox. The air filter includes a porous framework in the shape of a C-shaped channel which houses a filter pad. The outer and inner surfaces of the framework are porous and substantially open. The framework is preferably of a relatively stiff, but deformable, open weave material bounded along its edges by a circumferential frame. The inner surface defines an access opening through which the filter pad can be inserted. The air filter is sized to cover a recirculating air inlet of the stove. Magnetic strips allow the air filter to be easily and quickly mounted to the stove without modification.