This N2O analysis device is provided with: a light source (11) which radiates laser light onto an exhaust gas (5) containing N2O, H2O and CO2; a light receiver (13) which receives the laser light that has been radiated onto the exhaust gas (5); a light source control unit (14a) of a control device (14), which controls the wavelength of the laser light radiated by the light source (11) to between 3.84 μm and 4.00 μm; and a signal analyzing unit (14b) of the control device (14), which calculates the N2O concentration by means of infrared spectroscopy, using the laser light received by the light receiver (13) and the laser light controlled by the light source control unit (14a) of the control device (14).