Introduction to the LEP experiment L3

Physical problems that require an experimental support in the planned L3 experiment of the LEP program are briefly described. The L3 experiment is necessary for solving the problems already predicted theoretically: 1. Detection of Z0 boson and intermediate W+W- bosons; measurement of their masses, full production cross sections and width of Z0→2 f anti f decay. 2. Detection of t-quark. 3. Check-up of the existence of Higgs particles. To solve these problems, a high resolution of measuring e, μ, γ; a possibility of their identification; reproducilibility of topology of events and decay vertices are necessary. For this purpose it is necessary to create new detectors with a high resolution. Electromagnetic and hadron calorimeters, a muon chamber, a track detector are discussed