A body of a hydrogen generator includes a reformer configured to generate
a reformed gas mainly containing hydrogen, a material passage configured
to supply a reforming material, which is a material for a reforming
reaction, to the reformer, a shifter configured to convert CO contained
in a reformed gas obtained from the reformer into CO2, a reformed gas
passage configured to supply the reformed gas obtained from the reformer
to the shifter, and a passage for the shifted gas obtained from the
shifter. The shifted gas passage and the material passage are adjacent to
each other with a shared horizontal wall interposed therebetween, and
thereby, heat from the shifted gas and radiant heat from the downstream
end face of the shifter are transferred to the reforming material that
travels in the material passage.