The use of an air diffuser can help overcome various respiratory problems by producing steam from the evaporation of herbal plant essential oils. A combination of the 1,8-cineole from Eucalyptus globulus essential oil and the andrographolide from Andrographis paniculata extract was used as the ingredient. It has potential as a COVID-19 herbal immunomodulator by acting as an inhibitor of SARS-CoV-2, increasing blood levels of IgG, and helping to relieve symptoms of any respiratory problems.