To provide an information recording/reproducing device capable of realizing stable verification with a simple circuit configuration.

A verifying signal is generated by using a divider circuit 2133 to divide the sum total signal of a 4-divided light receiving element 2001 for receiving the reflected light of a recording optical stop 174 for information recording/reproducing by the sum signal of light receiving elements 2002 and 2003 for receiving the reflected lights of monitoring optical spots 175 and 176 for generating a tracking control signal. Thus, a verifying signal having any changes in the quantity of recording spot light accompanying information recording eliminated is obtained in a stable manner.