PURPOSE: To accurately count up the number of passed vehicles by detecting the existing positions of vehicles based on plural video signals every fixed period, detecting the traveling states of individual vehicles and counting up the number of passed vehicles.

CONSTITUTION: The front and rear parts of each vehicle are detected from video signals generated from a video input part 1 every fixed period and the different existing positions of the vehicle are detected and registered in a vehicle position table 11. Marks 1, 0 based on a passage flag forming part 4 are also registered in the table in accordance with the forward and backward movement of the vehicle. The forward vehicle passed through a prescribed position is identified by a vehicle identification part 5 in accordance with the contents registered in the table 11 to count the number of passed vehicles. Since a speed measuring method by which errors may be easily generated is not used, the number of passed vehicles can be accurately measured.