An optical information read/write apparatus according to the present invention includes: a light source 1 that emits a laser beam to access an information storage medium optically; a laser driver 51a for supplying drive current to a semiconductor laser as the light source 1; an RE superimposed current generator 51c for adding RE superimposed current to the drive current; a temperature sensor 35 for detecting a temperature around the light source 1; and a control section for switching the values of the RE superimposed current according to the temperature detected.