PURPOSE: To enable a ranging information on the side of a ranging visual field suited to a main object to be ranged to be automatically selected by laying stress on an adjacent or a wide visual field information.

CONSTITUTION: Visual field changeover switches 12W15 change over between a narrow visual field ranging condition for arithmetically processing signals from a first photosensitive device 5b by an arithmetic processing circuit 16 and at least one of an adjacent visual field ranging condition for arithmetically processing signals from second photosensitive devices 5a and 5c by the circuit 16 and a wide visual field ranging condition for arithmetically processing signals from the first photosensitive device 5b and the second photosensitive devices 5a and 5c by the circuit 16. On the other hand, a microcomputer 17 controls the switches 12W15 and detects whether or not a ranging information in the narrow visual field ranging condition obtained by the circuit 16 is larger than a predetermined range. When larger, the ranging information in the adjacent or wide visual field ranging condition and, when not larger, either of ranging informations after those in the narrow, adjacent and wide visual field ranging conditions are compared, is made the result of ranging information.