We have proposed a high-speed and large-capacity radio frequency identification (RFID) inventory method combining frame slotted ALOHA and binary tree. For the rapid inventory of a large number of tags, 1-bit flags are used as tag existence confirmation in the proposed method. The inventory time performance with erroneous 1-bit flags was evaluated. In the case of less than 100 tags and 1-bit flag error rate of less than 0.01, the degradation of the whole inventory time from the error free condition was less than 7.7%. We have compared the inventory time between the proposed method and the conventional standards. In the case of less than 100 tags, the whole inventory time of the proposed method was 2.4 - 15 times faster than that of the conventional standards.