A broadband modulation PLL includes a PLL portion containing a voltage controlled oscillator (101), a frequency divider (105), a phase comparator (104) and a loop filter (103). A frequency-dividing ratio of the frequency divider (105) is controlled to apply modulation, and also an input voltage of the voltage controlled oscillator (101) is controlled to apply modulation. One of phase modulation data for controlling the frequency dividing ratio and phase modulation data for input voltage of the voltage controlled oscillator (101) is inverted in phase by using an inverter (113), and the delay control circuit (110) detects a timing error on the basis of a signal (133) achieved by adding the output signals (131) and (132) of the filter (106) and the loop filter (103), and the timing is controlled by the delay circuits (111) and (112) to correct, the timing error.