Anomalous magnetic moment of the muon

The anomalous magnetic moment of the muon, $a_\mu$, is a unique quantity that allows high-precision tests of the Standard Model. Currently, a difference of 3 to 4 standard deviations is observed between the prediction of the Standard Model and the most precise measurement performed. We present a review of the Standard Model calculations of $a_\mu$. The principles and history of $a_\mu$ experiments are presented, and the recent measurement at the Brookhaven National Laboratory, USA, is described in detail. Prospects for further improving the accuracy of both calculations and measurements of $a_\mu$ are discussed.