To encode multi-channel digital data by adjusting the number of bits allocated to each channel to perform entropy coding of the multi-channel data, there is provided a multi-channel encoder including n encoders for audio data from n channels and an inter-channel bit allocator that allocates the number of bits usable for each channel on the basis of the provisional number of in-use bits from each of the encoders. Each of the encoders performs entropy coding on the basis of the provisional number of quantizing steps, outputs the provisional number of in-use bits resulting from summing of a code length of each unit of coding, and adjusts the number of in-use bits by updating the quantizing steps correspondingly to the number of bits supplied based on the provisional number of in-use bits. Also, the inter-channel bit allocator allocates the total number of usable bits as the number of bits determined correspondingly to a ratio of each provisional number of in-use bits with the sum of all the proportional numbers of in-use bits.