Abstract: An electronic endoscope includes a charge coupled device and provides macro-zooming function. The endoscope comprises an imaging unit including a plurality of optical elements forming an optical system and a support and guide mechanism for supporting and/or guiding the optical elements. The optical elements include a fixed lens, movable lenses, and a CCD. The support and guide mechanism comprises a casing including inner and outer cylinders. The axis of the inner cylinder defines a reference axis. A cam cylinder is fitted over the inner cylinder and is guided for rotational movement with no axial movement. An axial slider is fitted over the cam cylinder and guided for axial movement with no rotational movement. The axial slider is driven for axial movement through a manipulating lever provided on a handpiece. First and second carriages are fitted in the inner cylinder and guided for axial movement with no rotational movement.