The present invention is one that, even while cooling exhaust gas without dilution, makes it possible to accurately measure particle concentration, and provided with: a particle concentration measurement device 2; a sampling cooling pipe 3 that cools the exhaust gas collected from an exhaust gas transfer pipe 200 to a measurable temperature of the particle concentration measurement device 2 without dilution, and introduces the cooled exhaust gas into the particle concentration measurement device 2; a temperature sensor 4 that detects temperature of the exhaust gas flowing into an exhaust gas inlet 31; and a calculation device 5 that, from the detected temperature by the temperature sensor 4 and the temperature of the exhaust gas introduced into the particle concentration measurement device 2, corrects measured particle concentration by the particle concentration measurement device 2 in real time to calculate the particle concentration of the exhaust gas flowing through the exhaust gas transfer pipe 200.