Provided is a fuel battery cell capable of suppressing absorption of water discharged from a manifold by a porous body disposed between a membrane electrode assembly and a separator, and so improving drainage performance. This fuel battery cell 1 includes: a porous passage 20c that is disposed to be opposed to a membrane electrode assembly 10m on a cathode side, and a separator 30 sandwiching the membrane electrode assembly 10m and the porous passage 20c, the separator including a cathode off-gas discharging through hole 32b through which cathode off-gas discharged from the porous passage 20c flows. The porous passage 20c has a sticking-out part 201 when viewed in the thickness direction of the separator 30, and the sticking-out part sticks out into the cathode off-gas discharging through hole 32b from a side of the membrane electrode assembly 10m, and a length of the sticking-out part 201 in a longer direction of the separator 30 is shorter than one side of the cathode off-gas discharging through hole 32b on the membrane electrode assembly 10m side.