A quality control apparatus for quality control of a production line including one or more production facilities, the quality control apparatus comprising: a facility information obtaining unit configured to obtain data about a facility state value indicating a state of a production facility observed when the production facility processes a product; a product information obtaining unit configured to obtain data about a product state value indicating a state of the product measured from the product processed by the production facility; a storage unit configured to store a data group of facility state values of a plurality of acceptable articles produced previously and a data group of product state values of the plurality of acceptable articles; a determination unit configured to determine, for a product determined to be a defective article, whether a product state value of the defective article is an abnormal value by comparing the product state value with an acceptable article distribution of product state values including the data group of product state values of the plurality of acceptable articles accumulated in the storage unit, and determine whether a facility state value observed when the defective article is processed is an abnormal value by comparing the facility state value with an acceptable article distribution of facility state values including the data group of facility state values of the plurality of acceptable articles accumulated in the storage unit; and an abnormality detection unit configured to determine that the production facility has an abnormality when the product state value and the facility state value of the defective article are both determined to be abnormal values; characterized in that the quality control apparatus further comprising an update unit configured to add, for a product determined to be an acceptable article, a product state value of the product to the data group of product state values accumulated in the storage unit; wherein when the abnormality detection unit determines that the production facility has an abnormality, the abnormality detection unit outputs abnormality information, automatically changes an operating condition of the production facility, or changes the operating condition of the production facility after receiving permission to change the operating condition of the production facility from a user; and wherein the abnormality information includes at least any of information identifying the production facility determined to have an abnormality, the facility state value determined to be an abnormal value, information identifying the product determined to be a defective article, or the product state value determined to be an abnormal value. a facility information obtaining unit configured to obtain data about a facility state value indicating a state of a production facility observed when the production facility processes a product; a product information obtaining unit configured to obtain data about a product state value indicating a state of the product measured from the product processed by the production facility; a storage unit configured to store a data group of facility state values of a plurality of acceptable articles produced previously and a data group of product state values of the plurality of acceptable articles; a determination unit configured to determine, for a product determined to be a defective article, whether a product state value of the defective article is an abnormal value by comparing the product state value with an acceptable article distribution of product state values including the data group of product state values of the plurality of acceptable articles accumulated in the storage unit, and determine whether a facility state value observed when the defective article is processed is an abnormal value by comparing the facility state value with an acceptable article distribution of facility state values including the data group of facility state values of the plurality of acceptable articles accumulated in the storage unit; and an abnormality detection unit configured to determine that the production facility has an abnormality when the product state value and the facility state value of the defective article are both determined to be abnormal values; characterized in that the quality control apparatus further comprising an update unit configured to add, for a product determined to be an acceptable article, a product state value of the product to the data group of product state values accumulated in the storage unit; wherein when the abnormality detection unit determines that the production facility has an abnormality, the abnormality detection unit outputs abnormality information, automatically changes an operating condition of the production facility, or changes the operating condition of the production facility after receiving permission to change the operating condition of the production facility from a user; and wherein the abnormality information includes at least any of information identifying the production facility determined to have an abnormality, the facility state value determined to be an abnormal value, information identifying the product determined to be a defective article, or the product state value determined to be an abnormal value.