A noise masking device includes: an acquisition unit that acquires (i) frequency information indicating a frequency of a noise in a vehicle or frequency-correlated information correlated to the frequency and (ii) vehicle information relating to a characteristic of the noise; a signal source that generates a masker signal for outputting a masker sound that masks the noise in the vehicle; a pitch-shifting unit that pitch-shifts the masker signal according to the frequency information or the frequency-correlated information acquired by the acquisition unit to generate a pitch-shifted masker signal; an adjustment unit that performs, on the pitch-shifted masker signal, an adjustment according to the vehicle information acquired by the acquisition unit to generate an adjusted masker signal; and an output unit that outputs the adjusted masker signal as the masker sound.