A target vector is coded by multi-stage vector quantization. A first stage of the coding of the target vector is performed using a first code vector stored in a first codebook. A scalar associated with a code of each first code vector is stored in an amplifier storing section. A third code vector is determined by multiplying a second code vector stored in a second codebook with the scalar, calculating a distance using the target vector, the first code vector and the third code vector, and performing a second stage of the coding of the target vector using a result of the distance calculation.