There is provided a clock transferring apparatus for synchronizing a pattern signal synchronized with a reference clock with a variable clock based on an oscillation source different from that of the reference clock, having a rate clock generating section for generating a rate clock whose number of pulses within a predetermined period is almost equal with a number of pulses of the variable clock within the predetermined period by thinning out the pulses within the reference clock, a pattern generating section for generating the pattern signal corresponding to the pulses of the rate clock and a FIFO memory that stores data of the pattern signal corresponding to the pulses of the rate clock and outputs the stored data corresponding to the pulses of the variable clock.