The present invention concerns the sector of leather treatment or working lines, in particular but not exclusively to tannery processings. In particular, the invention relates to a tendentially automatic or semi-automatic apparatus for loading incoming leathers on one of these lines, the apparatus being provided with means for lifting and advancing individual leathers starting from a stacking station, and with systems for the spread out and sequential arrangement of the single leathers on a conveyor surface of the line, downstream of the apparatus.