To detect the decline of the terminal voltage of a battery, to use an obstacle detector in a normal state at all times and to help the sate and independent walking of a sight disabled person.

This white cane for the sight disabled person is provided with an obstacle detection means 20 provided with a sensor part 21 for detecting an obstacle and an obstacle alarming device 22 for performing alarming when the sensor part 21 detects the obstacle, the battery B for supplying power to the obstacle detection means 20 and a power supply switch 30 for turning ON/ OFF power supply to the obstacle detection means 20. In this case, a power supply reporting means 50 for reporting to a user when the terminal voltage of the battery B exceeds a voltage required for operating the obstacle detection means 20 when the power supply switch 30 is turned ON and a voltage decline alarming means 40 for alarming the user when the terminal voltage of the battery B becomes lower than the voltage required for operating the obstacle detection means 20 are provided.