To accurately move a pickup 31 along a radial line of an optical disc in an optical disc apparatus for recording signals on both sides of the disc or reproducing the signals from the both sides, the pickup 31 is mounted on a support base 30 coupled to transport means and movable by being guided by a U-shaped guide assembly 5 which is fixedly and accurately positioned on a chassis carrying a disc drive motor. The guide assembly 5 comprises a pair of straight travel guide portions disposed in parallel to each other on opposite sides of the plane of rotation of the disc, and a circular-arc guide portion interconnecting the two guide portions. When reproducing the recorded signals, the pickup 31 accurately reciprocatingly moves on the disc radial line along the straight travel guide portions, and when the reproduction position is changed from one side of the disc to the other side, the pickup quickly moves upward or downward along the circular-arc guide portion.