An audio device capable of easily generating two or more sets of surround signals based on 2-channel stereo signals and a method for generating surround sound are provided. The audio device 100 includes: an SL signal generation section 20 and a BL signal generation section 40 as first surround signal generation units for receiving an L signal and an R signal as 2-channel stereo signals, extracting a component of the R signal having high correlation with the L signal, subtracting the component from the L signal, thereby generating a first surround signal; and an SR signal generation section 30 and a BR signal generation section 50 as second surround signal generation units for extracting a component of the L signal having high correlation with the R signal, subtracting the component from the R signal, thereby generating a second surround signal. The level of subtracting a component from the L signal or the R signal for generating the first or second surround signal is differentiated each other between the plural sets.