The objective of this paper is to propose a new homography-based approach to image-based visual servoing. The visual servoing method does not need any measure of the 3D structure of the observed target. Only visual information measured from the reference and the current image are needed to compute the task function (isomorphic to the camera pose) and the control law to be applied to the robot. The control law is designed in order to make the task function converge to zero. We provide the theoretical proof of the existence of the isomorphism between the task function and the camera pose and the theoretical proof of the local stability of the control law. The experimental results, obtained with a 6 d.o.f. robot, show the advantages of the proposed method with respect to the existing approaches.