Disclosed is a novel hybrid polymeric electrolyte formed of a closed-cell cellular polymer foam impregnated with a non-aqueous electrolytic liquid, which comprises a plurality of closed cells defined by cell walls constituting a continuous solid-phase matrix which is impregnated with the non-aqueous electrolytic liquid to form a continuous solid-phase domain, in which the plurality of closed cells are substantially filled with a non-aqueous electrolytic liquid to form a plurality of liquid phase domains which are dispersed in the above-mentioned continuous solid-phase domain. The hybrid polymeric electrolyte of the present invention has not only high ionic conductivity and high mechanical strength, but also has the ability to prevent the non-aqueous electrolytic liquid from leakage. The non-aqueous electrochemical device comprising the hybrid polymeric electrolyte of the present invention exhibits excellent electrochemical performance, and also retains electrolytic liquid well.