AbstractDeposition of aerosols. Modern measuring techniques have created the conditions necessary for testing and improvement of deposition processes developed in practice. Glass‐fibre mechanical filters are highly effective for low aerosol concentrations. Collection of fine dusts and mists is accomplished by processes employing a combination of several deposition mechanisms. The deposition performance of fibre filters for exhaust air purification has been improved to such an extent that process air can now be recycled, avoiding emissions and saving energy. Thus aerosol deposition technology has already reached a high level of performance. The feasibility of combining high deposition efficiency, reliability, and economy has already been demonstrated in individual case