Fuel cell gas supply and diffusion layer, fuel cell separator and fuel cell stack

A fuel cell gas supply and diffusion layer comprising:

• a sheet-like porous body layer capable of gas permeating and gas diffusing, and having conductivity;
• and
• a plurality of gas passage grooves formed on one surface of the porous body layer in parallel and formed in a zigzag shape or a wave shape from an inflow side to an outflow side of the gas respectively, wherein
• as viewed in a plan view, in a plurality of rectangular regions R which circumscribe each gas passage groove of the plurality of gas passage grooves, a first rectangular region R1 where circumscribes one gas passage groove and a second rectangular region R2 where circumscribes a gas passage groove adjacent to the one gas passage groove overlap along a region in contact each other, and an overlapping region R3 where the first rectangular region R1 and the second rectangular region R2 overlap exists at any depth position of the plurality of gas passage grooves regardless of the cross-sectional shape of the plurality of gas passage grooves.