Vape shop employees and electronic cigarette users expose themselves to fine particles (PM2.5, aerodynamic diameter <2.5 μm) and ultrafine particle (aerodynamic diameter <100 nm), which can impose risks on their health. This study evaluated the efficiency of an air purifier as a potential mitigation strategy to reduce exposure with a total of 8 real-time sampling sessions. The study found positive results on the association between the application of the air purifier and particle number concentration reduction regardless of puff frequency, whereas PM2.5 mass concentration reduced significantly at only high puff frequency. Additional spatial analysis is recommended to optimize placement of air purifiers. In short, scientific inquiry into the efficacy of air purifiers in vape shops could help provide the background to regulate indoor air quality in vape shops, if determined necessary for protecting public health and workers’ health.