We review the 10 year long journey into the miniaturization and integration of matter wave optics resulting in devices mounted on surfaces, so called atom chips. The first experiments started with the guiding of atoms with free standing wires and investigated the trapping potentials in simple geometries. Atom optical elements can now be micro fabricated down to 1 um size on atom chips. The creation of a Bose-Einstein condensate in miniaturized surface traps was recently achieved, and the first attempts to integrate light optics are in progress.

In this review, we describe microscopic atom optics elements using current carrying and charged structures. Experiments with free standing structures (`atom wires') are reviewed, investigating the basic principles of microscopic atom optics. We then discuss the miniaturization on the atom chip. One of the open central questions is dealt with: what happens with cold atoms close to a warm surface, how fast will they heat up or lose their coherence? The review concludes with an outlook of what we believe the future directions to be, and what can be hoped for.