An image pickup apparatus which is improved in space efficiency for an optical system element, thereby reducing the apparatus size when a lens barrel is retracted. An image pickup apparatus includes a zoom lens barrel that moves between a retracted position and a shooting position in an optical axis direction to thereby change a photographing magnification. A prism bends an optical beam incident from a lens group of the lens barrel. A diaphragm-shutter element is capable of moving along the direction of the second optical axis together with a stepping motor for actuating the diaphragm-shutter element. The stepping motor is disposed, at least when the lens group is in the retracted position, at a position where the stepping motor overlaps the prism in parallel with the second optical axis.