Abstract
The beta decay of F20 has been investigated with a magnetic lens spectrometer. The decay proceeds mainly to the first excited state of Ne20 by a beta ray of maximum energy 5.419±0.013 Mev, followed by a gamma ray of energy 1.627±0.005 Mev. The excited state transition, with comparative half-life ft=9.73×104 seconds, has the allowed shape down to 1 Mev.