A coding apparatus for coding a speech signal and/or an audio signal, the coding apparatus including a plurality of coding layers for performing coding processes together, the coding apparatus comprising: a global gain calculating section adapted to calculate a global gain for spectrum data inputted to the plurality of coding layers, normalize the spectrum data by using the global gain, and output the global gain and the normalized spectrum data; a searching section adapted to divide the normalized spectrum data output from the global gain calculating section to generate a plurality of subbands, perform a neighborhood search on a spectrum of each of the plurality of subbands to calculate lattice vectors for the spectra of the plurality of subbands, and output the lattice vectors; a coding section adapted to perform multi-rate indexing for each of the plurality of subbands using a corresponding one of the lattice vectors received from the searching section, to generate index information indicating a result of the multi-rate indexing for each of the plurality of subbands; a selecting section adapted to determine, as a specific subband group in the plurality of coding layers, a selection range of subbands using the number of coding bits assigned to each of the plurality of subbands in the index information and a subband energy which is an energy of each of the plurality of subbands, and to output a position of the beginning subband in the specific subband group as band coded information, wherein the selection range of subbands is a range in which a total number of the coding bits is equal to or less than a preset value and a total of the subband energies is the highest among the plurality of subbands, and wherein the selection range of subbands is a set of continuous subbands in a case where the plurality of subbands are arranged in ascending or descending order of frequency; an adjusting section adapted to receive the band coded information output from the selecting section, rearrange the index information such that a part corresponding to the specific subband group in the index information is located at the top of the index information by using the index information and the band coded information which are received from the selecting section, and output the rearranged index information and the band coded information; and a multiplexing section adapted to multiplex the global gain received from the gain calculating section with the rearranged index information and the band coded information received from the adjusting section, and to generate and output coded information of said plurality of coding layers. a global gain calculating section adapted to calculate a global gain for spectrum data inputted to the plurality of coding layers, normalize the spectrum data by using the global gain, and output the global gain and the normalized spectrum data; a searching section adapted to divide the normalized spectrum data output from the global gain calculating section to generate a plurality of subbands, perform a neighborhood search on a spectrum of each of the plurality of subbands to calculate lattice vectors for the spectra of the plurality of subbands, and output the lattice vectors; a coding section adapted to perform multi-rate indexing for each of the plurality of subbands using a corresponding one of the lattice vectors received from the searching section, to generate index information indicating a result of the multi-rate indexing for each of the plurality of subbands; a selecting section adapted to determine, as a specific subband group in the plurality of coding layers, a selection range of subbands using the number of coding bits assigned to each of the plurality of subbands in the index information and a subband energy which is an energy of each of the plurality of subbands, and to output a position of the beginning subband in the specific subband group as band coded information, wherein the selection range of subbands is a range in which a total number of the coding bits is equal to or less than a preset value and a total of the subband energies is the highest among the plurality of subbands, and wherein the selection range of subbands is a set of continuous subbands in a case where the plurality of subbands are arranged in ascending or descending order of frequency; an adjusting section adapted to receive the band coded information output from the selecting section, rearrange the index information such that a part corresponding to the specific subband group in the index information is located at the top of the index information by using the index information and the band coded information which are received from the selecting section, and output the rearranged index information and the band coded information; and a multiplexing section adapted to multiplex the global gain received from the gain calculating section with the rearranged index information and the band coded information received from the adjusting section, and to generate and output coded information of said plurality of coding layers.