Assuming that exit pupil position is fixed, it is presented a zoom lens having a focusing mechanism which does not give rise to any changes in the angular field of view. A frontal part set in front of the zooming part consists of two movable components for focusing. The paraxial condition in which no focus breathing phenomena exist is, in general, derived. Explicit expressions of component-displacement are obtained together with the relation to one-movable component focusing method. According to the analysis, a zoom lens is designed to show the usefulness of the analysis.