A speaker is provided in the present disclosure. The speaker includes a membrane, a voice coil connected to the membrane, and a vibration part attached on the membrane. The membrane includes a main body and a periphery portion surrounding the main body. One of the vibration part and the main body includes a protrusion protruding away from the voice coil, and the other one of the vibration part and the main body includes a recess portion recessed towards the voice coil and corresponding to the protrusion.