The invention aims to provide a polymer electrolytic material excellent in
proton conductivity and also excellent in fuel shutting property, and
accordingly provide a polymer electrolytic fuel cell with a high
efficiency. That is, the invention provides a polymer electrolytic
material having an unfreezable water ratio Rw1 defined by the following
expression (S1) in a range of 20 to 100% by weight in hydrated state:
Rw1=[Wnf/(Wfc+Wnf)].times.100 (S1) in which Wnf represents the
unfreezable water content per 1 g of the polymer electrolytic material in
dry state and Wfc represents the low freezing point water content per 1 g
of the polymer electrolytic material in dry state.