In the previous immune complex transfer enzyme immunoassay for anti-HTLV-I IgG, the transfers of polystyrene beads in and out of test tube were handled with tweezers, and the bound β-D-galactosidase activity was measured with a fluorometer. The use of tweezers was considered the primary cause of false-positivity by carryover. Furthermore, the testing of many samples using a tweezer as a means of transfer was difficult. In the present immune complex transfer enzyme immunoassay, polystyrene beads were attached to plates through cylindrical bars and were used in microplate wells. Therefore, no tweezers were required. The bound β-D-galactosidase activity was measured with a fluororeader. This allowed the elimination of false-positivity due to carryover and made it easier to test many samples with higher sensitivity and reliability.