It is possible to generate an interpolation signal in which spectrum in frequency characteristics develops in a continuous manner according to a reproduced music without increasing the sampling rate (sampling frequency) in up-sampling processing. A high-frequency interpolation device 1 includes: a frequency band determination section 2 that determines a bandwidth type of an audio signal as a frequency band determination value preset for each bandwidth according to the frequency characteristics of the audio signal; and an interpolation signal generation section 3 that selects a filter coefficient of a high-pass filter in accordance with the frequency band determination value 2, performs filtering for the audio signal by using the high-pass filter having the selected filter coefficient, and generates a high-frequency interpolation signal for the audio signal.