We report on the neutrino mass measurement result from the first four-week science run of the Karlsruhe Tritium Neutrino experiment KATRIN in spring 2019 .
Beta-decay electrons from a high-purity gaseous molecular tritium source are energy analyzed by a high-resolution MAC-E filter .
A fit of the integrated electron spectrum over a narrow interval around the kinematic endpoint at 18.57 keV gives an effective neutrino mass square value of ( -1.0 ~ { } ^ { + ~ { } 0.9 } _ { - ~ { } 1.1 } ) eV ^ { 2 } .
From this we derive an upper limit of 1.1 eV ( 90 \% confidence level ) on the absolute mass scale of neutrinos .
This value coincides with the KATRIN sensitivity .
It improves upon previous mass limits from kinematic measurements by almost a factor of two and provides model-independent input to cosmological studies of structure formation .