A sound processing device (100, 200, 300, 400) comprising: a sound collection unit configured to collect a sound; an application unit configured to apply a predetermined filter to a signal of the sound collected by the sound collection unit; a selection unit configured to select a filter coefficient of the filter applied by the application unit; a beamforming unit (103, 301) configured to perform beamforming by using the sound collected by the sound collection unit; a filter coefficient storage unit adapted to store a filter coefficient C(f,k) used in the beamforming unit (103, 301); and a correction unit configured to correct the signal from the application unit, characterized in that the selection unit selects the filter coefficient C(f,k) on the basis of an instruction from a user, the instruction including a direction of a noise, wherein the beamforming unit (103, 301) includes a main beamforming unit and secondary beamforming unit adapted to prevent a sound from being changed at a moment when a filter coefficient C provided from the filter coefficient storage unit is switched, the main beamforming unit and secondary beamforming unit each being adapted to output beamformed signals, when the filter coefficient C(f,k) is switched, wherein the sound processing device (100, 200, 300, 400) further comprises a signal transition unit adapted to mix the beamformed signals from the main beamforming unit and the secondary beamforming unit on the basis of the expression: D f k = α D main f k + 1 − α D sub f k and to output the mixed signals to the signal correction unit, wherein D(f,k) is an output signal from the signal transition unit after switching of the filter coefficient, D main (f,k) is a signal from the main beamforming unit, D sub (f,k) is a signal from the secondary beamforming unit, wherein f is a frequency band, and k is a frame index, and wherein α is a coefficient having a value from 0.0 to 1.0, and is a value set by the designer arbitrarily, or α is a variable value and is set to be 1.0 when the filter coefficient C(f,k) is switched and reduces as the time passes, and set to be 0.0 when an arbitrarily set number of transition frames passes. a sound collection unit configured to collect a sound; an application unit configured to apply a predetermined filter to a signal of the sound collected by the sound collection unit; a selection unit configured to select a filter coefficient of the filter applied by the application unit; a beamforming unit (103, 301) configured to perform beamforming by using the sound collected by the sound collection unit; a filter coefficient storage unit adapted to store a filter coefficient C(f,k) used in the beamforming unit (103, 301); and a correction unit configured to correct the signal from the application unit, characterized in that the selection unit selects the filter coefficient C(f,k) on the basis of an instruction from a user, the instruction including a direction of a noise, wherein the beamforming unit (103, 301) includes a main beamforming unit and secondary beamforming unit adapted to prevent a sound from being changed at a moment when a filter coefficient C provided from the filter coefficient storage unit is switched, the main beamforming unit and secondary beamforming unit each being adapted to output beamformed signals, when the filter coefficient C(f,k) is switched, wherein the sound processing device (100, 200, 300, 400) further comprises a signal transition unit adapted to mix the beamformed signals from the main beamforming unit and the secondary beamforming unit on the basis of the expression: D f k = α D main f k + 1 − α D sub f k and to output the mixed signals to the signal correction unit, wherein D(f,k) is an output signal from the signal transition unit after switching of the filter coefficient, D main (f,k) is a signal from the main beamforming unit, D sub (f,k) is a signal from the secondary beamforming unit, wherein f is a frequency band, and k is a frame index, and wherein α is a coefficient having a value from 0.0 to 1.0, and is a value set by the designer arbitrarily, or α is a variable value and is set to be 1.0 when the filter coefficient C(f,k) is switched and reduces as the time passes, and set to be 0.0 when an arbitrarily set number of transition frames passes.