The diagnostic device disclosed in this application is a device for diagnosing liver condition. The diagnostic device comprises a nitric oxide sensor and an information output unit. The nitric oxide sensor can be brought into contact with hepatocytes making up the liver and detects the concentration of nitric oxide produced by the hepatocytes. The information output unit, based on the nitric oxide concentration detected by the nitric oxide sensor, outputs information for diagnosing the condition of the liver. The information output unit can, for example, output a graph showing the change over time in the nitric oxide concentration detected by the nitric oxide sensor.
