A multiple gas detection device comprising: a first cell part provided with a first electrochemical cell having a first solid electrolyte having oxide ion conductivity, a first electrode arranged on one side surface of the first solid electrolyte, and a second electrode arranged on the other side surface of the first solid electrolyte, a second cell part provided with a second electrochemical cell having a second solid electrolyte having oxide ion conductivity, a third electrode arranged on one side surface of the second solid electrolyte, and a fourth electrode arranged on the other side surface of the second solid electrolyte, a third cell part provided with a third electrochemical cell having a third solid electrolyte having oxide ion conductivity, a fifth electrode arranged on one side surface of the third solid electrolyte, and a sixth electrode arranged on the other side surface of the third solid electrolyte, an inlet diffusion controller arranged so as to introduce measured gas from outside and controlling diffusion of measured gas passing through it, and a measured gas chamber partitioned and formed by the first solid electrolyte, the second solid electrolyte, the third solid electrolyte, and the inlet diffusion controller, the measured gas chamber having a first measured gas chamber, a second measured gas chamber, and a third measured gas chamber, these first measured gas chamber, second measured gas chamber, and third measured gas chamber being arranged so as to be separated from the inlet diffusion controller in the order of the first measured gas chamber, the second measured gas chamber, and the third measured gas chamber, the first electrode being arranged inside the first measured gas chamber, the third electrode being arranged inside the second measured gas chamber, the fifth electrode being arranged inside the third measured gas chamber, and the second electrode, the fourth electrode, and the sixth electrode being arranged so as to be exposed to a reference gas, wherein the first cell part is configured to selectively detect a concentration of NOx or ammonia contained in measured gas in the first measured gas chamber, the second cell part is configured to make oxygen contained in measured gas in the second measured gas chamber move from the third electrode to the fourth electrode and convert NO 2 and ammonia contained in measured gas in the second measured gas chamber to NO, and the third cell part is configured to detect a concentration of NO contained in measured gas in the third measured gas chamber. a first cell part provided with a first electrochemical cell having a first solid electrolyte having oxide ion conductivity, a first electrode arranged on one side surface of the first solid electrolyte, and a second electrode arranged on the other side surface of the first solid electrolyte, a second cell part provided with a second electrochemical cell having a second solid electrolyte having oxide ion conductivity, a third electrode arranged on one side surface of the second solid electrolyte, and a fourth electrode arranged on the other side surface of the second solid electrolyte, a third cell part provided with a third electrochemical cell having a third solid electrolyte having oxide ion conductivity, a fifth electrode arranged on one side surface of the third solid electrolyte, and a sixth electrode arranged on the other side surface of the third solid electrolyte, an inlet diffusion controller arranged so as to introduce measured gas from outside and controlling diffusion of measured gas passing through it, and a measured gas chamber partitioned and formed by the first solid electrolyte, the second solid electrolyte, the third solid electrolyte, and the inlet diffusion controller, the measured gas chamber having a first measured gas chamber, a second measured gas chamber, and a third measured gas chamber, these first measured gas chamber, second measured gas chamber, and third measured gas chamber being arranged so as to be separated from the inlet diffusion controller in the order of the first measured gas chamber, the second measured gas chamber, and the third measured gas chamber, the first electrode being arranged inside the first measured gas chamber, the third electrode being arranged inside the second measured gas chamber, the fifth electrode being arranged inside the third measured gas chamber, and the second electrode, the fourth electrode, and the sixth electrode being arranged so as to be exposed to a reference gas, wherein the first cell part is configured to selectively detect a concentration of NOx or ammonia contained in measured gas in the first measured gas chamber, the second cell part is configured to make oxygen contained in measured gas in the second measured gas chamber move from the third electrode to the fourth electrode and convert NO 2 and ammonia contained in measured gas in the second measured gas chamber to NO, and the third cell part is configured to detect a concentration of NO contained in measured gas in the third measured gas chamber.