A water quality analyzer comprising: a combustion tube for burning a liquid sample inside; a sample injector (6; 8) configured to execute sample injection operation into the combustion tube ; a pressure sensor configured to detect pressure inside the combustion tube ; a temperature sensor configured to detect a temperature of the combustion tube ; and a determination part configured to determine whether the combustion tube and/or the sample injector (6; 8) is normal or abnormal based on an output of the pressure sensor and an output of the temperature sensor immediately after execution of the sample injection operation by the sample injector (6; 8), wherein the determination part is configured to detect presence or absence of a fluctuation in an output of the pressure sensor and presence or absence of a fluctuation in an output of the temperature sensor immediately after execution of the sample injection operation by the sample injector (6; 8), and, based on a result of the detection, determine whether the combustion tube and/or the sample injector (6; 8) is normal or abnormal, and the determination part is configured to determine that the combustion tube and the sample injector (6; 8) are normal when detecting a fluctuation in the output of the pressure sensor , to determine that the combustion tube is abnormal and the sample injector (6; 8) is normal when detecting only a fluctuation in the output of the temperature sensor , and to determine that the sample injector (6; 8) is abnormal when not detecting any fluctuation in either the output of the pressure sensor or the output of the temperature sensor . a combustion tube for burning a liquid sample inside; a sample injector (6; 8) configured to execute sample injection operation into the combustion tube ; a pressure sensor configured to detect pressure inside the combustion tube ; a temperature sensor configured to detect a temperature of the combustion tube ; and a determination part configured to determine whether the combustion tube and/or the sample injector (6; 8) is normal or abnormal based on an output of the pressure sensor and an output of the temperature sensor immediately after execution of the sample injection operation by the sample injector (6; 8), wherein the determination part is configured to detect presence or absence of a fluctuation in an output of the pressure sensor and presence or absence of a fluctuation in an output of the temperature sensor immediately after execution of the sample injection operation by the sample injector (6; 8), and, based on a result of the detection, determine whether the combustion tube and/or the sample injector (6; 8) is normal or abnormal, and the determination part is configured to determine that the combustion tube and the sample injector (6; 8) are normal when detecting a fluctuation in the output of the pressure sensor , to determine that the combustion tube is abnormal and the sample injector (6; 8) is normal when detecting only a fluctuation in the output of the temperature sensor , and to determine that the sample injector (6; 8) is abnormal when not detecting any fluctuation in either the output of the pressure sensor or the output of the temperature sensor . <EOS>