Abstract: Provided is a method for detecting an anomaly and a system, to which the method is applied. The anomaly detection method according to the embodiment of the present disclosure is a method performed by at least one computing device and comprises obtaining a plurality of models trained to detect an anomaly for different monitoring items, wherein input data of the models include at least one identification field for identifying an anomaly detection target, forming at least one model group by grouping models having a common identification field in the input data among the plurality of models, and detecting an anomaly of a detection target identified by a common identification field of the model group based on a detection result of a model group, wherein the input data of the models may include at least one identification field for identifying an anomaly detection target.