An information recording apparatus includes: a recording device capable of recording information into a data area of an information recording medium, by irradiating laser light, in conformity with a predetermined error correction method; an optimum-recording-power detecting device for obtaining an optimum recording power of the laser light, by recording test writing data into a data area portion with a length which is equal to or less than an allowable defect length in the predetermined error correction method, within the data area, by using the recording device; and a controlling device for controlling the recording device to record the information into the data area with the obtained optimum recording power.