A semiconductor integrated circuit generating a stabilized oscillation signal based on an input signal includes a plurality of unit circuits connected in series, each of the unit circuits having at least an oscillator, a divider, and a phase comparator which construct at least one part of a phase-locked loop. In the unit circuit, a frequency of an oscillation output signal of a latter one of the unit circuits is higher than that of an oscillation output signal of a former one of the unit circuits.