To provide a method for easily mass-producing extra-short fibers ≤1.0 mm, especially shorter than 0.1 mm, in length from a fiber bundle formed by bundling groups of multifilaments in a condition of being arranged in parallel.

The method for producing the extra-short fibers comprises the following practice: A plurality of to-be-cut materials (1) comprising fiber bundles (1a) made by arranging parallel and bundling a number of groups of multifilaments encapsulated in an encapsulant (1b) that is solidified by cooling and gasified or liquefied by heating are prepared, a group of the to-be-cut materials (1) with a cut edge face (F) formed perpendicularly to the fiber length direction is fixed so that the cut edge face (F) is horizontal, the cut edge face (F) is flatly cut by at least one cutting blade (4), and the encapsulant (1b) is removed from the resultant flatly cut materials (1), thus obtaining the objective extra-short fibers with a fiber length of 0.005-1.0 mm.