PURPOSE: To prevent a large number of non-conforming chips form developing by a method wherein the ships having the predetermined shape are prepared easily in a short period of time at the change of the shape of the chip or the like.

CONSTITUTION: After a group of strands made of molten thermoplastic resin is extruded from a die head 1, run down on the down-running chutes 4 of a guiding device 3 and guide rolls 5 together with cooling water so as to be cooled and solidified, the group of strands are pulled down with nip rolls 27 and, at the same time, cut into chips with a fixed cutter 28 and a rotary cutter 29. In order to manufacture chips, the data consisting of the diameter of the strand and the length of the chip, both of which are set with a setting device, the diameter of the strand measured with a diameter measuring device 38 and the length of the chip measured with a length measuring device 39 are processed by microcomputer so as to control the respective servo motors 16, 30 and 31 of the respective guide rolls 5, the nip rolls 27 and the rotary cutter 29.