  Superkamiokande atmospheric neutrino data for 414 days are analyzed in the
framework of three flavor oscillations with mass hierarchy. It is shown that
the best fit point is very close to the pure maximal
$\nu_\mu\leftrightarrow\nu_\tau$ case and $\Delta m^2 \simeq 7\times10^{-3}$
eV$^2$. The allowed region at 90 %CL is given and the implications to the long
baseline experiments are briefly discussed. It is also shown that the threefold
maximal mixing model fits to the data of atmospheric neutrinos and the reactor
experiments for $\Delta m^2 \sim 1\times10^{-3}$ eV$^2$.
