PURPOSE: To perform an easy and precise position detection by providing first and second marker detectors, a direction signal generating means, a detection signal delay means, and an UP/DOWN counter.

CONSTITUTION: Direction signals are generated by a direction signal generating means 3 on the basis of the detection results of a first marker detector 1 and a second marker detector 2, the output signal of the detector 1 or detector 2 is delayed by a detection signal delay means 4, and the increment or decrement of the output signal of the delay means 4 is performed according to the respective direction signals by an UP/DOWN counter 5 to detect the position according to the moving direction and moving quantity of a moving body. In this case, the respective direction signals cause delays of the same degree to the moving quantity of the moving body regardless of the moving direction, and a count miss can be canceled every reversion of the moving direction of the moving body. Since the count miss at the change of the direction signals can be prevented, the precise position of the moving body can be detected with a simple structure.