NO<SUB>3</SUB> and N<SUB>2</SUB>O<SUB>5</SUB> are important as intermediates of NOx loss in the nocturnal atmosphere. In this study, laser-in-duced fluorescence (LIF) technique is applied for measuring NO<SUB>3</SUB> and N<SUB>2</SUB>O<SUB>5</SUB> in the atmosphere. A tunable dye laser pumped by a pulsed Nd: YVO<SUB>4</SUB> laser was utilized as an excitation light source. NO<SUB>3</SUB> was excited around its 623-nm absorption peak and the induced fluorescence was detected. For measuring N<SUB>2</SUB>O<SUB>5</SUB>, thermal decomposition of N<SUB>2</SUB>O<SUB>5</SUB> was carried out and then generated NO<SUB>3</SUB> was detected. As a result of improvement and calibration of the instrument, the limits of detection for NO<SUB>3</SUB> and N<SUB>2</SUB>O<SUB>5</SUB> reached 4 and 6 pptv, respectively (<I>S/N</I>=1, 10-min averaging). A measurement test of N<SUB>2</SUB>O<SUB>5</SUB> was conducted in the urban atmosphere to check the applicability of the instru-ment. The LIF instrument is promising to measure atmospheric NO<SUB>3</SUB> and N<SUB>2</SUB>O<SUB>5</SUB>. This is a successful case of ap-plying a spectroscopic method to the environmental chemistry.