an input setting method for a protective relaying apparatus including an input setting switch for setting data , a digital operational device for carrying out a relaying operation utilizing the data , and a memory device for storing the data , the method comprising the steps of setting the data by the input setting switch , storing the data thus set in the memory device , comparing the set data with the stored data , carrying out the relaying operation utilizing the data when the compared data are found equal , and issuing an alarm signal when the compared data are found to be unequal .