PROBLEM TO BE SOLVED: To provide a concentrator for increasing particle concentration in a device for generating aerosol.SOLUTION: The concentrator includes an engraved acceleration plate having a plurality of slit-shaped acceleration channels extending in a radial direction, and an engraved deceleration plate 7120 having a plurality of slit-shaped deceleration plate channels extending in a radial direction. A plurality of acceleration channel outlet openings have an interval from a base surface of the outlet side of the acceleration plate, and a plurality of engraved deceleration channel inlet openings have an interval from a base surface of the inlet side of the deceleration plate such that a relatively large gap 7300 generated between the acceleration plate base surface and the deceleration plate base surface allows a waste volume flow rate to be discharged through the relatively large gap with a low flow resistance. The plurality of openings include at least two openings having different length.
