The present invention provides a DLL circuit performing a phase adjustment in accordance to an output load, and capable of adjusting the phase in a shot time. In the present invention, in a delayed lock loop (DLL) circuit that generates a control clock having a prescribed phase relationship with a reference clock by delaying the reference clock, the operating delay time of an output buffer is measured and the timing of the control clock is adjusted in accordance with this operating delay time. As a result, the timing of the output clock of the first variable delay circuit delay circuit is adjusted in accordance with the magnitude of the external load. This output clock or the output clock of a separate variable delay circuit subject to the same delay control is then utilized as a control clock.