A speaker is disclosed in which a split resonance of a diaphragm main body and a natural resonance of an edge are controlled, achieving a high sound quality while realizing a weight reduction. A diaphragm is composed of a diaphragm main body and an edge. An outer peripheral part of the diaphragm main body is bonded with a peripheral edge of a frame through the edge. An external shape of edge is formed in substantially a perfect circle. While, at least one of the outer peripheral part of the diaphragm main body and an inner peripheral part of the edge, which is a mutual bonding portion, is formed in a different shape than the perfect circle.