Described is an air filtering device (1) comprising a base module (3) which can be connected to a source of electrical power supply and comprising at least one fan (20) for moving air. The air filtering device (1) comprises: at least one filtering module (2) which can be connected to the base module (3) and which houses at least one air filtering element (6). The base module (3) and/or filtering module (2) have fluid dynamic connecting means defining a conduit for passage of air for placing in fluid communication the fan (20) and the filtering element (2). The base module (3) and the filtering module (2) have respective mechanical connections (12, 13) configured to form a stable mechanical connection between the modules. The base module and the filtering module have respective electrical connections (15, 17) for transmitting an electrical power supply between the base module and the filtering module, the electrical connections (15, 17) and mechanical connections are configured in such a way that the mechanical coupling between the mechanical connections (12, 13) of the base module and of the filtering module automatically also determines a simultaneous engagement between the electrical connections (15, 17).
