Biosafety Level 4 (BSL-4) laboratories are required for research on microorganisms that are highly pathogenic to humans and for which there are no prevention or treatment methods. Currently, the majority of BSL-4 laboratories in more than 60 around the world are suit-type laboratories using positive pressure protective suits. In 2021, the first suit-type BSL-4 laboratory in Japan was constructed at Nagasaki University. Positive pressure protective suits are important as primary barriers to protect workers from pathogens, but the selection process has been largely unexplored. Here, I describe the selection process for the positive pressure protective suits to be used at the BSL-4 laboratory of Nagasaki University, and introduce a novel positive pressure protective suit (PS-790BSL4-AL), which was originally designed and produced in Japan.