PURPOSE: To enable a distance between an originating place and ski plate to be displayed and the ski plate position to be confirmed even through a voice by emitting ultrasonic waves to measure the present position of the ski plate.

CONSTITUTION: When a skier having a transmitter-receiver 1 built in an apparatus forgets where his own ski plate is placed, he uses the transmitter-receiver 1 to emit ultrasonic waves. Then, a transmitter-receiver 5 mounted to a plate 11 receives the ultrasonic waves. A processor 2 recognizes the frequency of the ultrasonic waves to compare it with the content previously registered in a memory. If the frequency is the same as the content, a command is sent to a voice drive device 8 to generate the output of voice from an output device 9. At the same time, a command is sent to the transmitter-receiver 5 through a signal 6 informing the reception of the output from the device 9 to emit the ultrasonic waves. The sent ultrasonic waves enter the main transmitter- receiver 1 to be transmitted to the processor (1) for processing the signal so that a distance through which the ultrasonic waves reach the processor is calculated to be sent to a LCD drive device 3 and a distance between the transmitting position and a ski plate is outputted to an LCD panel 4.