Experimental Studies of the Nucleon Spin Structure: from the Past to the Future

Twenty two years ago the "proton spin crisis" has been declared after the European Muon Collaboration at CERN had found that total quark spin constitutes only a small fraction of the proton spin. This result is now confirmed, a large gluon polarisation in the proton seems unlikely and measurements of the parton angular momenta have started only recently. Therefore the "proton spin puzzle" is still alive. A review of the longitudinal and transverse nucleon spin structure is presented. Future of the experimental spin physics is discussed.