A signal correction device including: an orthogonal transform section configured to perform an orthogonal transform for an input signal that includes a speech as a target signal and an unnecessary non-target signal; an interval determining section configured to determine whether each frame of the input signal is an interval in which the non-target signal is dominantly included; a suppressing gain calculating section configured to calculate suppressing gain for suppressing the non-target signal for each first frequency band width for a frame determined to be the interval, and to calculate suppressing gain for suppressing the non-target signal for each second frequency bandwidth for a frame determined not to be the interval; and a signal correcting section configured to perform a signal correcting process for suppressing the non-target signal for a transform coefficient acquired by the orthogonal transform section by using the suppressing gain.