To provide a compact fuel reforming apparatus which has a low cost fuel air supply means to the burner of a reformer and which can be used at a low running cost.

This apparatus includes the reformer 3, a carbon monoxide transformer 4, a carbon monoxide remover 5, and a steam generator 2 all housed inside one chassis 21, and is provided with a fuel air blower 12A outside the chassis 21. Air compressed and supplied by the fuel air blower 12A into the chassis 21 is sent to the fuel air supply port of the burner 3a in the reformer 3 where the fuel off gas discharged from a fuel cell body 6 is burned to heat a catalyst layer in the reformer 3.