In a filter device, a filter coefficient calculation circuit has a parameter table. The parameter table stores a plurality of sets of filter coefficients associated with a first parameter based on a frequency and a second parameter based on respective plurality of levels representing a degree of attenuation or enhancement of a gain of a filter in filter characteristics. The filter coefficient calculation circuit extracts a set of filter coefficients from a parameter table with the use of the first parameter and the second parameter determined according to a frequency and a strength of a musical sound signal, and outputs the extracted set of filter coefficients to the filter. The filter circuit performs filter processing for the musical sound signal, based on the filter characteristics determined by the set of filter coefficients.