Conventional measurements of specific antibodies to food antigens were affected by the large amount of non-specific immunoglobulins in serum. Although many modifications to correct sensitivity have been described, more sensitive and more reliable method was desirable to be developed especially for noninvasive diagnosis. Our new sensitive enzyme immunoassay method as the immune complex transfer enzyme immunoassay method for antibodies to two food antigens, β-lactoglobulin and ovalbumin, was developed. For anti-β-lactoglobulin antibody, serum specific antibody was reacted simultaneously with 2,4-dinitrophenylbovine serum albumin-β-lactoglobulin conjugate and β-lactoglobulin-peroxidase conjugate. The complex formed of the three components was trapped onto polystyrene balls coated with anti 2,4-dinitrophenyl group IgG, eluted with N-2,4-dinitrophenyl-L-lysine and transferred to polystyrene balls coated with IgG against human IgG γ-chain for IgG class antibody and human IgA α-chain for IgA class antibody. Bound peroxidase activity was determined by fluorometry. For anti-ovalbumin antibody, ovalbumin conjugates were used instead of β-lactoglobulin conjugates. This assay method was 100- to 1,000-fold more sensitive than the conventional ELISA method. It was found by this method that dietary protein-specific IgG class antibody was in all healthy subjects examined.