Abstract: A vacuum cleaner comprises a housing having a floor-engaging nozzle fluidly interconnected with a filter bag in a closed filter bag chamber in the housing through a suction passageway, an exhaust vent in the filter bag chamber to exhaust filtered air exiting from the filter bag chamber and a vacuum motor provided in the housing to draw air from the floor-engaging nozzle to the filter bag. An exhaust filter is mounted in the exhaust vent. A sensor in the filter bag chamber detects a condition representative of the flow of air through the exhaust filter element and an exhaust filter indicator interconnected with the sensor provides a signal to a user when the condition reaches a predetermined level to indicate a clogged condition of the exhaust filter. A sensor and indicator can also be provided for the filter bag so that independent signals can be generated relating to the clogged condition of one or both of the filter bag and exhaust filter.