A nebulizer kit includes an atomizer generating an aerosol, and a particle sorting route communicating with the atomizer and sorting liquid particles in the aerosol to adjust a particle diameter distribution thereof, and guiding the aerosol to a discharge port. The particle sorting route includes a first particle sorting route with a uniform cross-sectional area in the first direction and a second particle sorting route with an inner end wall that curves from the first direction toward a second direction included in the same plane as the first direction. The first particle sorting route guides the aerosol to the second particle sorting route in the first direction, and the inner end wall of the second particle sorting route guides the aerosol in the second direction while aerosol particles with a certain particle diameter or more are attached thereto.