A gas component measuring device comprising: a cyclone that has a gas inlet ; and a laser gas analyzer configured to take, in the cyclone , a measurement of a component of a subject gas that contains particulate matter and is introduced into the cyclone through the gas inlet , wherein: the cyclone has a pair of opening portions , opposed to each other, in a side surface thereof; a light emitting portion of the laser gas analyzer is disposed so as to emit laser light into the cyclone through one of the pair of opening portions , and a light receiving portion of the laser gas analyzer is disposed so as to receive the laser light that exits through the other of the pair of opening portions ; and the gas component measuring device further includes a displacing device configured to reduce the particulate matter on an optical path of the laser light by hindering passage of the particulate matter in a vicinity of each of the pair of opening portions within the cyclone , wherein the displacing device includes a gas injection device configured to inject purge gas inward through each of the pair of opening portions , and/or the displacing device includes a hollow pipe provided so as to protrude inward from each of the pair of opening portions . a cyclone that has a gas inlet ; and a laser gas analyzer configured to take, in the cyclone , a measurement of a component of a subject gas that contains particulate matter and is introduced into the cyclone through the gas inlet , wherein: the cyclone has a pair of opening portions , opposed to each other, in a side surface thereof; a light emitting portion of the laser gas analyzer is disposed so as to emit laser light into the cyclone through one of the pair of opening portions , and a light receiving portion of the laser gas analyzer is disposed so as to receive the laser light that exits through the other of the pair of opening portions ; and the gas component measuring device further includes a displacing device configured to reduce the particulate matter on an optical path of the laser light by hindering passage of the particulate matter in a vicinity of each of the pair of opening portions within the cyclone , wherein the displacing device includes a gas injection device configured to inject purge gas inward through each of the pair of opening portions , and/or the displacing device includes a hollow pipe provided so as to protrude inward from each of the pair of opening portions . the cyclone has a pair of opening portions , opposed to each other, in a side surface thereof; a light emitting portion of the laser gas analyzer is disposed so as to emit laser light into the cyclone through one of the pair of opening portions , and a light receiving portion of the laser gas analyzer is disposed so as to receive the laser light that exits through the other of the pair of opening portions ; and the gas component measuring device further includes a displacing device configured to reduce the particulate matter on an optical path of the laser light by hindering passage of the particulate matter in a vicinity of each of the pair of opening portions within the cyclone , wherein the displacing device includes a gas injection device configured to inject purge gas inward through each of the pair of opening portions , and/or the displacing device includes a hollow pipe provided so as to protrude inward from each of the pair of opening portions . <EOS>