A numerical control device is disclosed having a parameter memory section 12B that stores discrete optimum parameters for respective operational modes, an operational mode setting switch 20 to allow operational modes to be selectively set through user's operation, and a defect content setting means for registering defect contents of machined results. The optimum parameter, suited for a particular operational mode selected and set with the operational mode setting switch 20, is retrieved for executing setting of the parameter while enabling setting of the parameter based on information obtained with the defect content setting means.