Disclosed herein is an apparatus for detecting infrasound. The apparatus for detecting infrasound includes a sound wave detector including a diaphragm dividing an inner space of a first container into a first space and a second space, and a microchannel assembly including a second container having an inner space with one of the spaces divided by the diaphragm and a plurality of microchannels having different resistance values with respect to transmission of a sound wave, and exposing the inner space of the second container to the air through one of the plurality of microchannels. Such an apparatus for detecting infrasound may have various cut-off frequencies according to the number of the microchannels.