A semiconductor device includes a delay amount measuring unit, multiple delay sections and a correction signal generating unit. The delay amount measuring unit for measures an actual delay amount corresponding to a specified delay amount by supplying a clock signal with a known period to multiple 1-ns-delay strings with a preassigned delay amount, and by detecting phase variations of the clock signal by the 1-ns-delay strings. The delay sections includes a delay string capable of freely adjusting a connection number of its delay elements. The correction signal generating unit generates a correction signal for enabling each of the delay sections to correct the connection number of the delay strings such that each delay section has a desired delay amount, in accordance with the actual delay amount corresponding to the specified delay amount and measured by the delay measuring unit.