A distance-measuring apparatus for a camera comprises an area sensor, an integration circuit, and a switching circuit. The above-mentioned area sensor receives light of a picture image in the image plane. The integration circuit integrates output signals of this area sensor. The control circuit controls operations of starting and stopping the integration of the above-mentioned integration circuit, based on output signals corresponding to a specific block of the above-mentioned area sensor. The switching circuit switches the above-mentioned specific block according to using state of the camera.