We have devised a new method of counting pollen allergen particles, modified from the fluorescent immunoblotting technique of Schumacher et al. Airborne Japanese cedar pollen allergens collected on Burkard's sampling tape were transferred onto a nitrocellulose membrane. The membrane was then treated with antiallergen mouse monoclonal antibody conjugated with alkaline phosphatase. Pollen allergens were detected as purple spots on the nitrocellulose membrane after phosphate substrate staining was performed. Pollen allergen particles were visible under a stereoscopic microscope or to the naked eye and could thus be counted easily. This new counting method takes less time than previous methods and requires no special skill.