Currently, threats caused by pathogens are serious public health problems worldwide. Protective clothing is essential when one is treating infected patients or dealing with unknown pathogens. Therefore, it is necessary to evaluate the performance of protective clothing against pathogens. In Japan, some methods for evaluating the performance of protective clothing have been established in the Japanese Industrial Standards (JIS). However, a test method against virus aerosols has not been established. Because there is a risk of infection from a live virus during the test, it is necessary to devise a safe method for the virus-aerosol-based test. Here, we propose a new method of safely measuring virus aerosols for the performance evaluation of protective clothing materials. To ensure safety, an inactivated virus was used. As a model virus, the influenza virus was selected owing to the proper small diameter of the virus particles. To quantitatively measure the particle-amount of the inactivated influenza virus, we developed an antigen-capture enzyme-linked immunosorbent assay (ELISA) targeting the M1 protein. Furthermore, we evaluated two materials using our method. Significant differences in the protection performance against the virus aerosol were observed between different sample materials, thereby confirming the applicability of our new method for performance evaluation.