A nebulizer kit comprising: an atomizing portion for generating an aerosol by atomizing a liquid; and a particle sorting route (111, 121, 131) that is in communication with the atomizing portion, and is for sorting particles of the liquid included in the aerosol so as to adjust a particle diameter distribution of the particles of the aerosol, and thereafter guiding the aerosol to a discharge port, characterized in that: the particle sorting route includes a first particle sorting route that extends in a first direction from near the atomizing portion and has a substantially uniform cross-sectional area in the first direction, a second particle sorting route that is in communication with the first particle sorting route and has an inner end wall that curves from the first direction toward a second direction included in substantially the same plane as the first direction, and a third particle sorting route that is in communication with the second particle sorting route and extends in a direction parallel to the first direction in a state of being shifted in a direction perpendicular to the first direction, the first particle sorting route guides the aerosol ejected from the atomizing portion in a direction substantially equal to the first direction to the second particle sorting route in the first direction, the inner end wall of the second particle sorting route guides the aerosol in the second direction, which is inclined with respect to the first direction, while particles with a particle diameter of a certain value or more among the particles of the aerosol are attached thereto, and the third particle sorting route has a cross-sectional area greater than an entire cross-sectional area of the second particle sorting route in the first direction, and allows the aerosol to flow to the discharge port, particles with a particle diameter of a certain value or more among the particles being attached to an inner wall thereof that is parallel with the first direction and is inclined with respect to the second direction. an atomizing portion for generating an aerosol by atomizing a liquid; and a particle sorting route (111, 121, 131) that is in communication with the atomizing portion, and is for sorting particles of the liquid included in the aerosol so as to adjust a particle diameter distribution of the particles of the aerosol, and thereafter guiding the aerosol to a discharge port, characterized in that: the particle sorting route includes a first particle sorting route that extends in a first direction from near the atomizing portion and has a substantially uniform cross-sectional area in the first direction, a second particle sorting route that is in communication with the first particle sorting route and has an inner end wall that curves from the first direction toward a second direction included in substantially the same plane as the first direction, and a third particle sorting route that is in communication with the second particle sorting route and extends in a direction parallel to the first direction in a state of being shifted in a direction perpendicular to the first direction, the first particle sorting route guides the aerosol ejected from the atomizing portion in a direction substantially equal to the first direction to the second particle sorting route in the first direction, the inner end wall of the second particle sorting route guides the aerosol in the second direction, which is inclined with respect to the first direction, while particles with a particle diameter of a certain value or more among the particles of the aerosol are attached thereto, and the third particle sorting route has a cross-sectional area greater than an entire cross-sectional area of the second particle sorting route in the first direction, and allows the aerosol to flow to the discharge port, particles with a particle diameter of a certain value or more among the particles being attached to an inner wall thereof that is parallel with the first direction and is inclined with respect to the second direction. the particle sorting route includes a first particle sorting route that extends in a first direction from near the atomizing portion and has a substantially uniform cross-sectional area in the first direction, a second particle sorting route that is in communication with the first particle sorting route and has an inner end wall that curves from the first direction toward a second direction included in substantially the same plane as the first direction, and a third particle sorting route that is in communication with the second particle sorting route and extends in a direction parallel to the first direction in a state of being shifted in a direction perpendicular to the first direction, the first particle sorting route guides the aerosol ejected from the atomizing portion in a direction substantially equal to the first direction to the second particle sorting route in the first direction, the inner end wall of the second particle sorting route guides the aerosol in the second direction, which is inclined with respect to the first direction, while particles with a particle diameter of a certain value or more among the particles of the aerosol are attached thereto, and the third particle sorting route has a cross-sectional area greater than an entire cross-sectional area of the second particle sorting route in the first direction, and allows the aerosol to flow to the discharge port, particles with a particle diameter of a certain value or more among the particles being attached to an inner wall thereof that is parallel with the first direction and is inclined with respect to the second direction.