In an error control apparatus on a receiving side using a hybrid ARQ which combines an error correcting encoding method and an automatic repeat request method, a buffer stores hard decision result data or soft output data instead of soft decision information in order to reduce a memory capacity of the buffer, and re-encodes the data stored to be provided to a combiner. Alternatively, the number of bits of the data stored in the buffer is restricted or a memory included in a decoder is used as an HARQ buffer.