Measurement of the W boson mass.

We present a measurement of the mass of the {ital W} boson using data collected with the Collider Detector at Fermilab during the 1992--93 collider run at the Fermilab Tevatron. A fit to the transverse mass spectrum of a sample of 3268 {ital W}{r_arrow}{mu}{nu} events recorded in an integrated luminosity of 19.7pb{sup {minus}1} gives a mass {ital M}{sub {ital W}}{sup {mu}}=80.310{plus_minus}0.205(stat){plus_minus}0.130(syst)GeV/{ital c}{sup 2}. A fit to 5718 {ital W}{r_arrow}{ital e}{nu} events recorded in 18.2 pb{sup --1} gives {ital M}{sup {ital e}}{sub {ital W}}=80.490{plus_minus}0.145(stat){plus_minus}0.175(syst)GeV/{ital c}{sup 2}. Combining these results, accounting for correlated uncertainties, yields {ital M}{sub {ital W}}=80.410{plus_minus}0.180GeV/{ital c}{sup 2}.