PURPOSE: To provide the subject ultrafine material having sufficient length to enable easy entanglement, giving a sheet material having the feeling of leather without using a binder, and composed of leather fibers having specific diameter and length and almost uniform thickness and randomly directed as a whole in untwined state.

CONSTITUTION: Leather scraps, etc., of natural leather generated from a production process of chrome-tanned leather product are preliminarily crushed to ≤3mm with a centrifugal crusher, etc., dispersed in water to obtain an aqueous dispersion having a concentration of 1-10wt.%, slurried by treating with a high pressure homogenizer, etc., and cast on a glass plate to form a film. The objective leather fiber material produced by the above process is composed of leather fibers having a diameter (measured in dried state) of 0.02-0.3μm and a length/ diameter ratio of ≥100 and randomly directed as a whole in untwined state.