PURPOSE: To obtain an automatic document input device with improved accuracy discriminating vertical writing or horizontal writing in the document.

CONSTITUTION: The device is provided with a document image reading part 1, an area dividing part 3, a character identifying part 5 and a document direction discriminating part 2 composed of a means selecting plural subareas within a document image area, a consecutive value output means outputting consecutive values corresponding to respective reliability in at least vertical, horizontal or undesignated direction of a document direction for the respective selected subareas and a document direction discrimination means integrating an output from the consecutive value output means with a neural network having the output node of at least vertical writing, horizontal writing or undesignated writing and finally discriminating the direction of the document, is provided between the document image reading part 1 and the area division part 3.