A document reading apparatus includes a feeding roller for feeding a
document, a reading unit for reading images of the document fed by the
feeding roller and a substantially U-shaped document transfer path for
guiding the document fed the feeding roller. The substantially U-shaped
document transfer path is constituted by an internal guide and an
external guide. The external guide is separated from the internal guide
by rotating the external guide. The internal guide is rotatably disposed
and supports the reading means. A reading transfer path in which the
reading unit is arranged is opened by rotating the internal guide.