A speech processing device includes a distance acquisition unit configured to acquire a distance between a sound collection unit configured to record speech from a sound source and the sound source, a reverberation characteristic estimation unit configured to estimate a reverberation characteristic based on the distance acquired by the distance acquisition unit, a correction data generation unit configured to generate correction data indicating a contribution of a reverberation component from the reverberation characteristic estimated by the reverberation characteristic estimation unit; and a dereverberation unit configured to remove the reverberation component from the speech by correcting the amplitude of the speech based on the correction data.