To provide a speaker apparatus capable of being easily fitted to the inside of a structure or the like and from which a sufficient acoustic effect can be obtained.

The speaker apparatus is provided with: a cylindrical outer yoke 11; a voice coil 12 fitted to an inner circumferential face of the outer yoke 11; a diaphragm 13 arranged concentric with the center line of the outer yoke 11; dampers 15A, 15B for supporting the diaphragm 13 in a freely vibrating way in a direction in parallel with a center line of the outer yoke 11; a plate 16 fitted to an outer circumferential part of the diaphragm 13 and opposed to the voice coil 12; magnets 17A, 17B fitted to the plate 16; and inner yokes 18A, 18B fitted to the magnets 17A, 17B and opposed to the inner circumferential part of the outer yoke 11.