1. A quality control system comprising: a plurality of medical facilities, each of which includes an automated analyzer for mixing a reagent with a sample to analyze a target component contained in the sample; a dedicated terminal connected to said automated analyzer at each facility; a first communication network connected to each dedicated terminal at each facility; collection means for collecting information about analysis parameters including a lot number of a standard solution used for calibration and a lot number of a standard solution used for quality control, and information about results of measuring the standard solution used for quality control and results of measuring the standard solution used for calibration, from each facility; a second communication network line connecting said collection means with said terminal of each facility for receiving and transmitting information; database storing means for storing the information collected by the collection means from each facility; a communication network line connecting said database storing means to said collection means for receiving and transmitting information; statistical-processing calculation means for calculating average and standard deviation values of measuring results of a standard solution used for calibration in the same standard solution lot, based on the information about analysis parameters including information of lot number of the standard solution used for calibration for each facility stored in said database storing means, and the information about the results of measuring the standard solution used for calibration for each facility stored in said database storing means; and information supplying means for supplying at least one of said average and standard deviation values calculated by said statistical-processing calculation means to the facility which includes the automated analyzer that measured the same standard solution of the same lot number used for calibration.