Abstract: A speaker diaphragm with a circular opening in a center zone thereof has a pattern of concave and convex sections formed on a front surface or a rear surface thereof. A plurality of concave and convex sections are formed in each of regions provided at a regular interval with a specific angle in a circumferential direction of the diaphragm. The concave and convex sections formed in each region have different sizes in a radial direction of the diaphragm. The concave and convex sections formed in adjacent regions are displaced from each other in the radial direction. The concave and convex sections formed on the diaphragm are aligned on at least a first and a second imaginary curved line, respectively, each imaginary curved line passing regions and approaching an inner periphery of the circular opening from an outer periphery of the diaphragm.