Searches at LEP

Twelve years of searches at LEP1 and especially LEP2 are summarized. Indirect searches, resulting from the accurate measurements of electroweak observables, are reviewed and the conclusions concerning the Higgs boson are recalled. Direct searches for this boson as well as for non-standard effects and particles are described. We quote the limits which have been set on their existence. we analyse the impact of all these results on the various models proposed to extend the Standard Model, in particular Supersymmetry, Compositeness and Extra-dimensions.