A solid oxide fuel cell includes an electrode including an electrolyte ceramic, and an anode electrode and a cathode electrode sandwiching the electrolyte ceramic from both sides, a metal frame located around the electrode so as to sandwich the electrode unit from both sides and physically contact each of the anode electrode and the cathode electrode, and a power supply port electrically connected to the metal frame to supply electric power of a high frequency to the metal frame. The electrode includes a reduced thickness portion in a predetermined concentratedly heated region.