The survival rates of airborne Bacillus subtilis var niger spores were shown to be about 35 % , 44 % and 35 % when exposed to the microwave irradiation for 1.5 min with high, medium and low power applied, respectively (p-value=0.37). In contrast, the airborne Pseudomonas fluorescens were shown to have lower survival rates of 5.8 % , 12.2 % and 21 % (p-value=0.0045). Similar patterns but higher survival rates at respective powers were observed for airborne Aspergillus versicolor exposure (p-value<.0001). For environmental bacterial and fungal bioaerosols, 30–40 % of them were shown to survive the high power microwave irradiation for 1.7 min. Outdoor bioaerosols were shown to have stronger survival than the indoor bioaerosols when exposed to the microwave irradiation. ESEM and TEM images showed visible damages to the microwave-irradiated microbes. The results obtained here can be used to develop microwave-based air sterilization technologies especially targeted for biological aerosols.