In an optical pickup device, heat conduction from a semiconductor laser to a pickup case is to be increased, thereby to prevent the semiconductor laser from deteriorating in performance, being reduced in durability and in committing erroneous actions, and to improve its reliability. An optical pickup device comprises a semiconductor laser for recording or playing back information onto or from an optical disk, a laser drive circuit to control the driving of the semiconductor laser, a pickup case for mounting the semiconductor laser and the laser drive circuit, and a signal transmitting flexible substrate for transmitting signals and the like to the semiconductor laser. To this optical pickup device is added a heat conducting flexible member for thermally connecting the semiconductor laser and the pickup case.