A learning device in a control system which comprises: a controller which outputs a command value (u) obtained by compensating a target value (r) based on a compensation amount (p); and a control object controlled to perform a predetermined process on an object to be processed, wherein a command value (u) output by the controller is input to the control object, and the control object outputs a control variable as a response to the command value (u), wherein the learning device provides, to an adjuster including a learned model learned to output the predetermined compensation amount (p) to the controller based on a specific parameter of the object to be processed, the learned model, and the learning device being characterized in that it comprises: an evaluation part which obtains operation data including the target value (r), the command value (u), and the control variable (y) to evaluate the quality of the control variable (y) by determining whether the control variable (y) is within a predetermined allowable range; a learning part which generates a candidate compensation amount (p*) based on the operation data, performs learning with the generated candidate compensation amount (p*) and the specific parameter of the object to be processed as teacher data, and generates a learned model; and a setting part which provides the learned model to the adjuster when the control variable (y) evaluated by the evaluation part is within the predetermined allowable range when the command value (u) obtained by compensating the target value based on the compensation amount output by the generated learned model is imparted to the control object. a controller which outputs a command value (u) obtained by compensating a target value (r) based on a compensation amount (p); and a control object controlled to perform a predetermined process on an object to be processed, wherein a command value (u) output by the controller is input to the control object, and the control object outputs a control variable as a response to the command value (u), wherein the learning device provides, to an adjuster including a learned model learned to output the predetermined compensation amount (p) to the controller based on a specific parameter of the object to be processed, the learned model, and the learning device being characterized in that it comprises: an evaluation part which obtains operation data including the target value (r), the command value (u), and the control variable (y) to evaluate the quality of the control variable (y) by determining whether the control variable (y) is within a predetermined allowable range; a learning part which generates a candidate compensation amount (p*) based on the operation data, performs learning with the generated candidate compensation amount (p*) and the specific parameter of the object to be processed as teacher data, and generates a learned model; and a setting part which provides the learned model to the adjuster when the control variable (y) evaluated by the evaluation part is within the predetermined allowable range when the command value (u) obtained by compensating the target value based on the compensation amount output by the generated learned model is imparted to the control object. an evaluation part which obtains operation data including the target value (r), the command value (u), and the control variable (y) to evaluate the quality of the control variable (y) by determining whether the control variable (y) is within a predetermined allowable range; a learning part which generates a candidate compensation amount (p*) based on the operation data, performs learning with the generated candidate compensation amount (p*) and the specific parameter of the object to be processed as teacher data, and generates a learned model; and a setting part which provides the learned model to the adjuster when the control variable (y) evaluated by the evaluation part is within the predetermined allowable range when the command value (u) obtained by compensating the target value based on the compensation amount output by the generated learned model is imparted to the control object.