Abstract: An apparatus for automatically analyzing gases in oil, wherein a gas analyzer analyzes the total quantity of combustible gases extracted from the oil or the quantities of several specified ones of the combustible gases, comprising a data processor determining the presence or absence of the abnormality of an oil-immersed equipment on the basis of the increasing or decreasing trend of the analyzed results obtained in several analyzing operations, or calculating the sampling period of oil sampling and analytical processing routines, on the basis of the increasing or decreasing trend of the analyzed results, whereby the abnormality can be automatically determined with a high reliability.