To provide an aroma generator capable of facilitating refill work of liquid aroma and evaporating and diffusing the liquid aroma at an optional timing of a user, and to provide a retaining member for use in the aroma generator.

An aroma generator 100 includes a container member 1, a retaining member 3, and an evaporation member 4. The container member 1 is formed into a bottomed cylindrical shape with an opening part 14 at one end, stores essential oil, and has a male screw part 12a. The retaining member 3 includes a female screw part 33 with which the male screw part 12a is engageable, is formed into a cylindrical shape, and stores and retains the container member 1. The evaporation member 4 is attached to at least either one of the container member 1 and the retaining member 3. The essential oil 1A infiltrates the evaporation member 4 and evaporates therefrom. The retaining member 3 has: a first cylindrical part 31 from one end of which the container member 1 is inserted; and a second cylindrical part 32 that is provided at the other end of the first cylindrical part 31 and where the evaporation member 4 is exposed to the outside from an end opposite to the first cylindrical part 31.