  We constrain energy spectra of supernova neutrinos through the avoidance of
an overproduction of the 11B abundance during Galactic chemical evolution. In
supernova nucleosynthesis calculations with a parametrized neutrino spectrum as
a function of temperature of mu- and tau-neutrinos and their antiparticles and
total neutrino energy, we find a strong neutrino temperature dependence of 11B
yield. When the yield is combined with observed abundances, the acceptable
range of the temperature of mu- and tau-neutrinos and their antiparticles is
found to be 4.8 and 6.6 MeV. Non-zero chemical potentials would reduce this
temperature range by about 10% for a degeneracy parameter smaller than 3.
