A steering angle of steered wheels and a vehicle speed of a fork-lift
truck are respectively detected by sensors (4, 5). A CPU (1) compares the
vehicle speed with a predetermined speed (S2), and causes a meter (6) to
display the steering angle when the vehicle speed is lower than the
predetermined speed (S4, S14), and causes the meter (6) to display the
vehicle speed when the vehicle speed not lower than the predetermined
speed (S3, S13). As a result, the space for the display device can be
reduced without affecting the operation efficiency of the fork-lift
truck.