The present invention comprises a first distance-measuring mode in which a subject distance is measured on the basis of a subject image signal produced by at least a pair of integration-type light-receiving elements receiving the light from subjects, and a second distance-measuring mode in which the subject distance is measured on the basis of the image signal a steady-light removing section has produced by removing the steady-light component from the subject image signal. In measuring the distance, the second distance-measuring mode is forced to be on for a specific time. On the basis of the resulting image signal, the main subject is estimated and a light-receiving sensor sensing area is selected. The light-receiving sensor sensing area is used for integration control in continuing to obtain the subject image signal.