In　this　work,　the　performance　of　a　novel　three-dimensional　carbon-based　planar　microsupercapacitor　(MSC)　electrode　structure　is　investigated.　An　in　situ　template-free　fabrication　of　the　Cu　nanowire　network　structure　acting　as　the　current　collector　is　first　prepared　through　a　chemical　oxidation　phase　of　sputtered　Cu　films,　followed　by　a　thermal　reduction　phase.　Carbon　is　subsequently　grown　over　the　Cu　nanostructure.　In　a　two-electrode　electrochemical　test,　the　patterned　interdigitated　carbon/Cu　nanowire　network　device　exhibits　an　excellent　maximum　areal　and　volumetric　capacitance　of　1.45　and　7.43　mF　cm-3,　respectively,　while　retaining　94.2%　of　its　capacitance　after　10　000　charge-discharge　cycles.　This　relatively　simple　foundry-compatible　fabrication　process　provides　an　excellent　method　in　which　planar　MSCs　can　be　patterned　and　fabricated　for　energy　storage　solutions　in　microelectronics.　Copyright　©　2019　American　Chemical　Society.