An apparatus for reading an image comprises an original mounting table for mounting an original, a first carriage which has a light source for irradiating light to the original and an optical system for guiding original-image light reflected from the original, and which moves along the original mounting table, a lens unit having a lens into which the original-image light enters and placed immediately under a passage on which the first carriage moves, a CCD assembly for receiving the original-image light passed through the lens and reading an image corresponding to the original-image light, a lens bracket cover having a bracket portion to which the CCD assembly is attached and a cover portion for covering the lens unit, and a lens base having the bracket portion of the lens bracket cover attached thereto, for supporting the lens unit.