Provided is an error correcting encoder and, more particularly, to an error correcting encoder used for an improved transmission method of the Advanced Television System Committee (ATSC), and a method thereof. The error correcting encoder for digital television broadcasting, which is suggested in the present research, includes a robust encoder for encoding a one-bit input into robust encoded data; a pre-coding block for receiving the robust encoded data and performing pre-coding to thereby produce a pre-coded signal; and a trellis encoding block for performing trellis encoding on the robust encoded data and the pre-coded signal.