Filtration device for an apparatus for ventilating and/or heating and/or air conditioning, especially for a motor vehicle and the apparatus with such a device

Filtration device intended to equip an aeration and/or heating and/or air conditioning apparatus, in particular for a motor vehicle, comprising a frame (22) partially surrounding at least a filter media (16) and sealing means, the frame comprising locking means (66, 68) capable of cooperating with the apparatus when the device is mounted in the latter: the sealing means consist of a flexible blade (46) with which the frame is provided, the locking means being capable of maintaining the blade in a deformed position so that it performs a sealing function while preventing disassembly of the device.