A decoding apparatus and method are capable of decoding LDPC codes with a high degree of precision while preventing the circuit scale of the decoding apparatus from increasing. A computation section carries out a first computation process corresponding to three check-node processes by making use of decoding intermediate results supplied from a decoding intermediate result storage memory by way of a cyclic shift circuit, and stores the result of the first computation process in a decoding intermediate result storage memory. A computation section carries out a second computation process corresponding to six variable-node processes by making use of decoding intermediate results supplied from a decoding intermediate result storage memory by way of a cyclic shift circuit, and stores the decoding intermediate result in the decoding intermediate result storage memory.