An image pickup apparatus having a plurality of image pickup modes and a zoom lens for use with the image pickup apparatus is configured such that, even if the dimension of an effective screen region of an image pickup element changes as a result of changeover of the image pickup mode, the change of the angle of view is moderated and good aberration correction can be achieved in any of the image pickup modes. In an image pickup apparatus (1), an additional lens set (G5) having a positive refractive power is positioned most adjacent the image side with respect to a zoom lens (2) for movement to and from a position on an optical axis of the zoom lens. Upon changeover of an image pickup mode, the additional lens set is moved to or away from the position on the optical axis to reduce or extend the focal length range of the zoom lens thereby to moderate the variation of the angle of view caused by a difference in dimension of the effective screen region of an image pickup element (12) when any different image pickup mode is selected. Further, the movement of the additional lens set to or from the position on the optical axis is detected to set the states of components in accordance with any image pickup mode.