To provide a method for correcting an edge of a recording pulse by which an edge position of the recording pulse is always corrected properly without depending on the factors of a circuit configuration, voltage and temperature, and an individual difference of a chip.

The method for correcting an edge of an recording pulse of this invention comprises; a step for producing a delay measuring pulse by delaying a reference clock; a step for ANDing two delay measuring pulses with different delays to measure the number of delay elements per unit delay time; a step for NORing two delay measuring pulses with different delays to measure the number of delay elements per unit delay time; a step for averaging a difference between the numbers of delay elements obtained by the AND measurement and NOR measurement to obtain a correction value for correcting the error of the number of delay elements produced by Duty collapse of delay measuring pulses; and a step for correcting the number of delay elements obtained by the AND measurement using the correction value.