An atomizer for an electronic cigarette includes an atomizing assembly, an adjusting assembly, a bottom cover, and a collecting device. The atomizing assembly is arranged on the bottom cover, and the collecting device is located between the bottom cover and the atomizing assembly. 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.
