Single W Production at LEP2

Single W and single gamma productions which are sensitive to the trilinear gauge coupling WWgamma have been studied at LEP. It is shown that single W production has particular sensitivity to the "anomalous" magnetic moment Kgamma of the W boson, complementary to WW production at LEP and Wgamma production at hadron colliders. The invisible decay of W boson has been searched and the limit on the invisible decay width of 27 MeV at 95% C.L. has been obtained.