The LD (laser diode) may be damaged or its performance may deteriorate due to such factors as electrostatic discharge from the human body, surge voltages from measurement equipment, leakage voltages from soldering irons, and packing materials. As a countermeasure against static electricity, the device, operator, work place and measuring jigs must all be set at the same electric potential. In using LD, observe the following precautions: To protect the device from static electricity charges which accumulate on the operator or the operator's clothes, use a wrist strap etc. to ground the operator's body via a high impedance resistor (1M). A semiconductive sheet should be laid on both the work table and the floor in the work area. When soldering, use an electrically grounded soldering iron with an isolation resistance of more than 10M. For containers for transportation and packing, use of antistatic material (material that minimizes the generation of static change when rubbed against or separated from itself or other similar materials). 2. Precautions for mounting