A solid oxide fuel cell comprising: a cathode including a complex oxide having a perovskite structure expressed by the general formula ABO 3, an anode, and a solid electrolyte layer disposed between the cathode and the anode, the content of P in the complex oxide is at least 1 ppm and no more than 50 ppm, the content of Cr in the complex oxide is at least 1 ppm and no more than 500 ppm, and the content of B in the complex oxide is at least 1 ppm and no more than 50 ppm in a weight ratio relative to the total weight of the complex oxide; and wherein (i) and/or (ii) applies: (i) a standard deviation value for the atomic percentage of respective elements in the A site measured using energy dispersive X-ray spectroscopy at 10 spots in a single field on a sectional surface of the cathode being no more than 10.4, the single field being a range observed by an electron microscope with a magnification of 100 times to 5000 times; (ii) a standard deviation value for the atomic percentage of respective elements in the B site measured using energy dispersive X-ray spectroscopy at 10 spots in a single field on a sectional surface of the cathode being less than or equal to 5.03, the single field being a range observed by an electron microscope with a magnification of 100 times to 5000 times. a cathode including a complex oxide having a perovskite structure expressed by the general formula ABO 3, an anode, and a solid electrolyte layer disposed between the cathode and the anode, the content of P in the complex oxide is at least 1 ppm and no more than 50 ppm, the content of Cr in the complex oxide is at least 1 ppm and no more than 500 ppm, and the content of B in the complex oxide is at least 1 ppm and no more than 50 ppm in a weight ratio relative to the total weight of the complex oxide; and wherein (i) and/or (ii) applies: (i) a standard deviation value for the atomic percentage of respective elements in the A site measured using energy dispersive X-ray spectroscopy at 10 spots in a single field on a sectional surface of the cathode being no more than 10.4, the single field being a range observed by an electron microscope with a magnification of 100 times to 5000 times; (ii) a standard deviation value for the atomic percentage of respective elements in the B site measured using energy dispersive X-ray spectroscopy at 10 spots in a single field on a sectional surface of the cathode being less than or equal to 5.03, the single field being a range observed by an electron microscope with a magnification of 100 times to 5000 times. (i) a standard deviation value for the atomic percentage of respective elements in the A site measured using energy dispersive X-ray spectroscopy at 10 spots in a single field on a sectional surface of the cathode being no more than 10.4, the single field being a range observed by an electron microscope with a magnification of 100 times to 5000 times; (ii) a standard deviation value for the atomic percentage of respective elements in the B site measured using energy dispersive X-ray spectroscopy at 10 spots in a single field on a sectional surface of the cathode being less than or equal to 5.03, the single field being a range observed by an electron microscope with a magnification of 100 times to 5000 times.