A sound image localization apparatus comprises a signal source for outputting an audio signal; a localization angle input unit for receiving an angle of a sound image to be localized; a coefficient control unit for receiving sound image localization angle information from the localization angle input unit, reading coefficients from a coefficient memory in accordance with the information, and outputting the coefficients; first, second, and third multipliers for multiplying the audio signal output from the signal source by using first, second, and third coefficients output from the coefficient control means, respectively; a first signal processing unit for receiving the output from the second multiplier, and processing it by using a filter having a predetermined first frequency response; a second signal processing unit for receiving the output from the second multiplier, and processing it by using a filter having a predetermined second frequency response; a first adder for adding the output from the first multiplier and the output from the first signal processing unit to output the sum; a second adder for adding the output from the third multiplier and the output from the second signal processing unit to output the sum; a first output unit for outputting the output of the first adder; and a second output unit for outputting the output of the second adder.