An atomizer (100, 200, 300, 400) comprising: an outer tube (11, 21, 31), a liquid storing member (142, 341, 3) received in the outer tube (11, 21, 31) and an atomizing head (15, 25, 35, 4) located at an end portion of the liquid storing member (142, 341, 3), wherein a liquid storing cavity (1421, 241, 3411) is formed in the liquid storing member (142, 341, 3), an air outlet channel (1423, 244, 3416) is formed between the outer tube inner wall and the liquid storing member outer wall, an atomizing cavity is formed in the atomizing head (15, 25, 35, 4), the atomizing cavity communicates with the liquid storing cavity (1421, 241, 3411) and the air outlet channel (1423, 244, 3416), and the liquid tobacco in the liquid storing cavity (1421, 241, 3411) enters in the atomizing cavity to be atomized into mist, which mixes with air and then flows out through the air outlet channel (1423, 244, 3416); a connecting portion is formed to be in communication with the liquid storing cavity by extending the end portion of the liquid storing member along the axial direction of the liquid storing member, the atomizing head comprises an atomizing head base, a liquid outlet communicating with the connecting portion is defined on the sidewall of the connecting portion, a penetration hole aligned with the liquid outlet is defined on the sidewall of the atomizing head base, when the connecting portion is received in the atomizing head base, the liquid outlet is capable of being communicated with the penetration hole; characterized in that the atomizing head further comprises a heating element and a liquid guiding element each sleeved on the atomizing head base, the two sides of the liquid guiding element are respectively tightly attached to the heating element and the atomizing head base, the atomizing cavity is formed by the inner space of the heating element, a smoke outlet communicating with the atomizing cavity and the air outlet channel is defined on the heating element. an outer tube (11, 21, 31), a liquid storing member (142, 341, 3) received in the outer tube (11, 21, 31) and an atomizing head (15, 25, 35, 4) located at an end portion of the liquid storing member (142, 341, 3), wherein a liquid storing cavity (1421, 241, 3411) is formed in the liquid storing member (142, 341, 3), an air outlet channel (1423, 244, 3416) is formed between the outer tube inner wall and the liquid storing member outer wall, an atomizing cavity is formed in the atomizing head (15, 25, 35, 4), the atomizing cavity communicates with the liquid storing cavity (1421, 241, 3411) and the air outlet channel (1423, 244, 3416), and the liquid tobacco in the liquid storing cavity (1421, 241, 3411) enters in the atomizing cavity to be atomized into mist, which mixes with air and then flows out through the air outlet channel (1423, 244, 3416); a connecting portion is formed to be in communication with the liquid storing cavity by extending the end portion of the liquid storing member along the axial direction of the liquid storing member, the atomizing head comprises an atomizing head base, a liquid outlet communicating with the connecting portion is defined on the sidewall of the connecting portion, a penetration hole aligned with the liquid outlet is defined on the sidewall of the atomizing head base, when the connecting portion is received in the atomizing head base, the liquid outlet is capable of being communicated with the penetration hole; characterized in that the atomizing head further comprises a heating element and a liquid guiding element each sleeved on the atomizing head base, the two sides of the liquid guiding element are respectively tightly attached to the heating element and the atomizing head base, the atomizing cavity is formed by the inner space of the heating element, a smoke outlet communicating with the atomizing cavity and the air outlet channel is defined on the heating element.