Combustor and fuel cell system including same

A combustor, comprising:

• a catalyst bed portion supporting a catalyst capable of promoting a combustion reaction of fuel;
• a vaporizer which is arranged on the downstream side of the catalyst bed portion with respect to a flow of the fuel going through the catalyst bed portion and is configured to be able to use a combustion gas generated from the combustion reaction as a hot fluid;
• a manifold portion which is outside the catalyst bed portion and guides air in a direction opposite to the flow of the fuel going through the catalyst bed portion and comprises a wall portion which is in contact with or shared with a sidewall of the vaporizer;
• and
• a fuel introducing portion configured to penetrate the wall portion of the manifold portion so that the fuel evaporated by the vaporizer can be introduced into the manifold portion, the fuel introducing portion having a pipe member extending from the vaporizer toward the manifold portion and protruding inside the manifold portion.