A loudspeaker is provided which includes: a magnetic circuit including a magnet having at least one hole, a plate fixed to one of a pair of polar surfaces of the magnet, and a box-shaped yoke having an inner bottom surface fixed to the other polar surface of the magnet; a voice coil vertically vibratably provided in a magnetic gap formed by the plate and the yoke; a diaphragm having a peripheral edge connected to an upper end of the voice coil; and a magnetic fluid filled in at least one of a gap between the voice coil and the plate and a gap between the voice coil and the yoke. The loudspeaker includes at least one means for uniformly distributing the magnetic fluid.