The absorption spectra of N₂O, H₂O vapor, CO, and CO₂ isotopes were analyzed in the spectral range λ= 4-5 μm, where a strong absorption band ν₃ of N₂O centered at ~2225 cm^-1 is located. To measure the absorption of N₂O in a real atmosphere in the presence of absorption of interfering atmospheric gases (H₂O vapor, CO, ¹²CO₂, ¹³CO₂), a number of N₂O absorption lines near λ=4.5 μm (vibrational-rotational band ν₃) and the corresponding radiation frequencies were selected, where the relative influence of the absorption of interfering atmospheric gases is minimal and amounts to no more than 2.2 %. For practical use, three optimal frequencies of rotational absorption lines in the ν₃ N₂O band near 4.5 μm are recommended, where the maximum sensitivity of N₂O detection is achieved with a minimum relative influence of the absorption of interfering atmospheric gases: 2234.01 cm^-1 (line R(12) N₂O); 2234.75 cm^-1 (line R(13) N₂O); 2240.43 cm^-1 (line R(21) N₂O). In this case, the minimum relative influence of the absorption of interfering atmospheric gases (1.8 %) is observed on the R(21) absorption line of the ν₃ N₂O band. Keywords: laser gas analysis of the atmosphere, photoacoustic gas analyzer of N₂O, detection of N₂O absorption, absorption band ν₃ of N₂O.