PURPOSE: To enable interruption of operation corresponding to a delimiter key upon detecting of an error, by checking the spelling of each word on the basis of data stored in a word data memory and data stored in a dictionary memory.

CONSTITUTION: Code data corresponding to character symbol keys 4W6 being inputted through a keyboard 3 are printed by means of a print mechanism and simultaneously written into a word memory 110. When word delimiter data stored in a delimiter data memory 104 in ROM53 is inputted, said data is written into a delimiter data memory 118 so as to check the data or words written into the word data memory 110. When the spelling is correct, operation corresponding to the delimiter data is executed. If input and printing of data are continued and an erroneous spelling is detected, an alarm buzzer sounds to interrupt operation corresponding to the delimiter data, or printing of period or comma is stopped. In this case, a correction key 23 is operated to erase the error character and print a correct spelling.