The serum levels of specific IgE antibodies to food allergens and inhalant allergens were evaluated in ninety five patients with bronchial asthma using the MAST system, which can measure specific IgE antibodies against sixteen different allergens with a single sample. 1. Higher positivities of specific IgE antibodies were found in inhaled allergens than in food allergens. Specific IgE antibodies against several allergens were detected in individuals more frequently in inhaled allergens than in food allergens. 2. Positivities of specific IgE antibodies against food allergens did not correlate to patients' age and patients' age at onset. In inhaled allergens, positive results in MAST system were frequently observed in patients under age of 50 and under age at onset of 60. 3. In subjects with high serum IgE levels, high positivities of specific IgE antibodies against inhaled allergens and food allergen were found. 4. The MAST system is suggested to be clinically more useful than RAST.