A speech/audio coding apparatus and method is provided. The number of encoding bits allocated to encoding of extended-band spectrum is reduced while degradation of sound quality in the extended band is suppressed. A band compression unit creates combinations of sub-band spectra in pairs of two samples each in order from a low-range side in a band compression target sub-band, selects a spectrum having a large absolute-value amplitude among the combinations, and arranges the selected spectrum close to the low-range side on a frequency axis. A number-of-units recalculation unit redistributes bits saved in the sub-band for which band compression was performed to a low range outside the extended band, and redistributes the number of units on the basis of the redistributed bits.