An audio coding device includes a memory; and a processor configured to execute a plurality of instructions stored in the memory, the instructions comprising: selecting a main lobe among a plurality of lobes detected from a frequency signal configuring an audio signal on a basis of bandwidth and power of the lobes; and coding the audio signal in such a manner that a first amount of bits per a unit frequency domain allocated to coding of the frequency signal of the main lobe is larger than a second amount of bits per the unit frequency domain allocated to the coding of the frequency signal of a side lobe as a lobe other than the main lobe.