A method for manufacturing a nanocrystalline alloy ribbon piece with high productivity is provided. The method according to the present disclosure is a method for manufacturing an alloy ribbon piece obtained by crystallizing an amorphous alloy ribbon piece, and includes: preparing the amorphous alloy ribbon piece; sequentially heating the ribbon piece from one end to an intermediate position toward another end to a temperature range equal to or more than a crystallization starting temperature, and stopping the heating when heating the ribbon piece up to the intermediate position; and sequentially heating the ribbon piece from the other end to a position immediately before the intermediate position to the temperature range. In the sequentially heating the ribbon piece from the other end, the ribbon piece is heated up to the position immediately before the intermediate position after the heating is stopped in sequentially heating the ribbon piece from the one end.