The malevolent use of Anthrax spores on civilians in 2001 has shown the necessity to protect citizens from criminal use of biological agents. The success of such attack depends on sufficient concentration of pathogens in a defined area. Detecting pathogenous bacteria, spores and viruses must be accomplished by triggering short-term alarm and identification of the type of threat. Since most the bio sensors available today are laboratory bound or require special equipment which needs training as well as experience, new systems are needed. The concept of BIO-PROTECT is the development of a fast-alert, easy-to-use device for detection and identification of airborne bacteria, spores, viruses and toxins. It is based on bioaerosol detection by fluorescence, scattering and background aerosol measurement followed by ionisation of air flow and analysis of the spectrum of relative speed of passage, enabling identification of biological agents.