PURPOSE: To avoid mixing-in of foreign materials without stopping an apparatus and open the subject bale by moving a fiber takeout device of a fiber opener for a fiber bale, mutually synchronizing the movement of a carriage and a fiber takeout device with a controller, detecting the foreign materials in the bale with sensors and removing the foreign materials.

CONSTITUTION: A fiber takeout device 3 such as an opener for a fiber material 1 is moved relatively to a bale 1 and the movement of a carriage 2 in the longitudinal direction and the vertical movement of the fiber takeout device 3 are mutually continuously synchronized with a controller 15 and foreign materials 12 in the bale 1, e.g. a metal piece, a wood piece, a foil or fibers of different kinds are detected with sensors 13a and 13b. An electrical signal is outputted to the controller 15 and the position of the foreign materials 12 is inputted to a memory 14 according the travel distance of a driving motor 16. The takeout device 3 is lifted from the bale 1 with a lifting motor 17 and further moved above the site of the foreign materials 12 in the operating direction and then lowered again onto the fiber bale 1. Thereby, the fiber bale 1 is opened.