  We discuss the mean-field dynamo action in protoneutron stars that are
subject to instabilities during the early evolutionary phase. The mean field is
generated in the neutron-finger unstable region where the Rossby number is
$\sim 1$ and mean-field dynamo is efficient. Depending on the rotation rate,
the mean-field dynamo can lead to the formation of three different types of
pulsars. If the initial period of the protoneutron star is short, then the
generated large-scale field is very strong ($> 3 \times 10^{13}$G) and exceeds
the small-scale field at the neutron star surface. If rotation is moderate,
then the pulsars are formed with more or less standard dipole fields ($< 3
\times 10^{13}$G) but with surface small-scale magnetic fields stronger than
the dipole field. If rotation is very slow, then the mean-field dynamo does not
operate, and the neutron star has no global field. Nevertheless, strong
small-scale fields are generated in such pulsars, and they can manifest
themselves as objects with very low spin-down rate but with a strong magnetic
field inferred from the spectral features.
