1. A vector quantization apparatus comprising: a classifier, included in a processor, that generates classification information indicating a type of a feature that includes a voice characteristic and is correlated with a quantization target vector among a plurality of types; a selector, included in a processor, that selects one first codebook according to the classification information, the selected first codebook being associated with the classification information and including a plurality of first code vectors, from a plurality of first codebooks associated with the plurality of types, respectively; a first quantizer, included in a processor, that acquires a first code by quantizing the quantization target vector using the plurality of first code vectors included in the selected first codebook; a scaling factor codebook comprising scaling factors associated with the plurality of types, respectively; and a second quantizer, included in a processor, that has a second codebook comprising a plurality of second code vectors and acquires a second code by quantizing a residual vector between one first code vector indicated by the first code and the quantization target vector, using the second code vectors and a scaling factor associated with the classification information.