A document reading apparatus includes a conveying unit configured to continuously convey a document having a series of sheets along a conveyance path, a reading unit configured to obtain image data by reading a sheet at a predetermined reading position, a storage unit configured to store the image data obtained by the reading unit, and a transfer unit configured to transfer the stored image data to a transfer destination. The transfer satisfies a relationship X+Y≧Z>X, wherein X represents a reading time required for the reading unit to read said sheet, Y represents an interval time between an end of reading said sheet and a beginning of reading a next sheet of the series, and Z represents a transfer time required for the transfer unit to transfer the image data stored in the storage unit to the transfer destination. A related method is also disclosed.