Provided is a technique that can generate a spread spectrum clock signal in all of an upper-spread mode, a down-spread mode, and a center-spread mode. A spread spectrum clock generator (2) spreads a spectrum of a signal with a predetermined carrier frequency to generate a spread spectrum clock signal under the control of a control unit (13). The control unit includes carrier frequency correction control means (13b). The carrier frequency correction control means shifts the predetermined carrier frequency to generate, from one spread mode, a spread spectrum clock signal of another pseudo spread mode.