Due　to　the　elimination　of　‘land/channel’　geometry　in　conventional　bipolar　plates,　metal　foam　as　flow　distributor　in　proton　exchange　membrane　fuel　cell　(PEMFC)　has　shown　great　potential　in　improving　the　uniformity　of　reactant　and　temperature　distributions,　which　is　beneficial　to　the　performance　enhancement　of　the　fuel　cell.　However,　the　arrangement　of　metal　foam　which　can　be　optimized　to　further　enhance　the　performance　of　PEMFC　has　not　been　considered　yet.　In　the　study,　nickel　metal　foam　is　used　as　a　new　type　of　flow　field　for　experimental　research,　and　compared　with　the　performance　of　conventional　graphite　parallel　flow　field　(case　1)　in　a　PEMFC.　With　respect　to　the　arrangement　of　metal　foam,　three　cases,　namely　the　use　of　metal　foam　either　in　the　anode　side　(case　2)　or　cathode　side　(case　3),　and　the　simultaneous　use　of　metal　foam　in　both　sides　(case　4),　were　designed.　Experimental　results　showed　that　nickel　metal　foam　flow　field　can　make　the　temperature　distribution　at　the　membrane　more　uniform,　which　is　conducive　to　the　durability　of　the　membrane,　and　improves　the　fuel　utilization　rate.　By　comparing　with　case　1　at　fully　humidified　condition,　the　increase　of　maximal　power　density　for　case　2　is　15.67　%,　which　is　higher　than　case　3　(6.36　%)　and　case　4　(9.09　%),　indicating　the　importance　of　the　arrangement　of　metal　foam.　The　interpretation　is　that　when　relative　humidity　(RH)　is　high,　the　cathode　side　using　nickel　metal　foam　flow　field　is　more　prone　to　flooding.　Furthermore,　a　3-hour　constant　current　test　on　case　1–4　indicated　that　at　RH　=　1,　a　serious　voltage　deterioration　was　observed　after　105　min　when　nickel　metal　foam　is　used　in　the　cathode　side.　With　the　decrease　of　RH,　the　critical　flooding　time　was　gradually　postponed.　This　finding　is　especially　useful　for　the　practical　applications　of　metal　foam　as　flow　distributor　in　a　PEMFC.　©　2021　Elsevier　Ltd