The atomization unit (111) includes a liquid holding member (12) for holding an aerosol source, a heating element (13) for atomizing the aerosol source held by the liquid holding member, and the aerosol for the liquid holding member The liquid holding member has a shape extending along the predetermined direction (A), and in the orthogonal direction (B) orthogonal to the predetermined direction. At least a part of the inner side surface of the liquid holding member is in contact with or close to the heating element, and at least a part of the outer side surface of the liquid holding member in the orthogonal direction is covered with the covering member.霧化ユニット（１１１）は、エアロゾル源を保持する液保持部材（１２）と、前記液保持部材によって保持される前記エアロゾル源を霧化する発熱体（１３）と、前記液保持部材に対する前記エアロゾル源の供給量を制限する被覆部材（１５）とを備え、前記液保持部材は、所定方向（Ａ）に沿って延びる形状を有しており、前記所定方向に直交する直交方向（Ｂ）における前記液保持部材の内側側面の少なくとも一部は、前記発熱体と接触又は近接しており、前記直交方向における前記液保持部材の外側側面の少なくとも一部は、前記被覆部材によって被覆される。
