An atomizer for an electronic cigarette includes an atomizing assembly, an adjusting assembly, a bottom cover, and a collecting device. The collecting device and the atomizing assembly are arranged on the bottom cover. The adjusting assembly includes a substrate with an injecting hole and an adjusting member. Size of the injecting hole is adjustable by rotating the adjusting member. The present application also provides another embodiment, which includes an atomizing assembly with an atomizer head and an air inlet pipe, and an adjusting assembly with an air inlet in fluid communication with the outside. One end of the air inlet pipe is communicated with the bottom of the atomizer head, and the other end of the air inlet pipe is in fluid communication with the air inlet. The atomizers have an anti-leakage function. The present application also provides an aerosol generating device with the atomizer.
