The structure of crystallised {[Cu4(pz)5.5][Cu2(2,2′-bim)3]0.5[P2W18O62]}·H2O (1) (pz = pyrazine, bim = biimidazole) is reported. The crystal structure is characterised by cage-like pores [Cu8(pz)11]8+ of Cu ions linked through pz ligands. [P2W18O62]6– polyanions are capsulated into cage-like pores of [Cu8(pz)11]8+, forming ‘hamburger’-like units. Furthermore, the three-dimensional framework in 1 is achieved via copper-pyrazolate layers, binuclear copper-biimidazole subunits, and Dawson-type polyoxometalate clusters. The electrochemical properties of compound 1 were also studied in detail.