A prototype virus sampler using electrostatic precipitation has been developed to investigate aerosol infection by SARS-CoV-2. The sampler consists of a discharge electrode placed inside a vial, and a thin layer of viral lysis buffer at the bottom, working as a collection electrode. The sampler was operated with the sampling air flow rate of 40 L/min. Collection efficiency of the sampler is about 80% for 25nm to 5.0µm diameter particles. We sampled the air of a food court of a commercial

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... y, a connecting corridor of a clouded train station, and two office rooms (A and B) in September 2021, just after the 5th peak of COVID-19 in Japan. The analysis using a RT-qPCR detected the virus RNA in the air of the office A, B and the food court. Estimated concentration of the virus in the air determined by calibration curve was 2.0 x 102, 7.8 x 102, and 0.6 - 2.4 x 102 copies/m3, in the office A, B, and the food court, respectively. These results indicate that the sampler using electrostatic precipitation can detect SARS-CoV-2 in indoor air. It could be developed as a risk assessment method for aerosol infection.