The present invention discloses a speaker having a frame, a vibrating system and a magnetic circuit system. The vibrating system has a vibrating diaphragm, a voice coil and an elastic supporting assembly. The magnetic circuit system has a main magnet, a secondary magnet and a magnetic plate having a main body and a supporting portion opposite to the elastic supporting assembly. The elastic supporting assembly has an avoiding hole penetrating there through and facing to the supporting portion. The yoke has a yoke body fixed on the frame and an extending portion extending from two opposite sides of the yoke body towards the supporting portion. The extending portion passes through the avoiding hole thereof and attach on the supporting portion. The speaker of the present invention has advantages of good reliability and excellent acoustic performance.