The commercially available radioallergosorbent test (RAST) is still widely used as a good diagnostic tool for diagnosis of allergic diseases. Recently, a new in vitro test (Pharmacia CAP System and MAST Immunosystems MAST System) was proposed to measure IgE antibodies in a quantitive manner. The MAST System is based on cellulose fiber in a sort of pipette. The carrier can bind many kinds of allergens in the CNBr (cyanogen bromide) activated form, compared to the RAST paper disc. In this study, we examined serum levels of specific IgE antibodies to food allergens and inhalant allergens in forty bronchial asthma patients using the MAST System. Higher positivities of specific IgE antibodies were found in inhaled allergens than in food allergens. Although high positivities of specific IgE antibodies against food allergens did not correlate to patient age or age at onset, positive reaction to inhaled allergens in the MAST System was frequently observed in patients under the age of 40 or in those under age 30 at onset. The MAST System, which can measure specific IgE antibodies against sixteen different allergens with a single sample, is suggested to identify a larger number of atopic patients than RAST.