PROBLEM TO BE SOLVED: To effectively reduce an influence of an ultra-low frequency sound of an ultra-low frequency generation source on an object 4.SOLUTION: An ultra-low frequency sound reduction device 10A comprises: a soundproof house 12; a microphone 14; a signal processing part 16; a controller 18; and a sound generation means 20. The microphone 14 is configured to detect information related to an ultra-low frequency sound S1 generated from an oscillation sieve device 22. A signal processing part 16 is configured to generate a signal of a phase reverse to that of the ultra-low frequency sound S1 generated from the oscillation sieve device 22 on the basis of the information detected by the microphone 14. The controller 18 is configured to allow the sound generation means 20 to generate an ultra-low frequency sound S2 of a phase reverse to that of the ultra-low frequency sound S1 which is large enough to offset the ultra-low frequency sound S1 generated from the oscillation sieve device 22 by driving the s
