The sensor sensitivity and the method of setting the peak selected area of the AF sensor are changed according to the luminance level of the distance measurement object. The distance measuring apparatus uses a passive AF sensor to determine the distance of a distance measuring object by sensor data obtained from the AF sensor, wherein: if the distance measurement object has high luminance, the sensor sensitivity is set at low sensitivity, the distance measurement area is divided into three areas, and sensor data is acquired for each area as a peak selected area of the AF sensor; if the distance measurement object has moderate luminance, the sensor sensitivity is set at low sensitivity, and sensor data is acquired with the entire area of the distance measurement area being the peak selected area of the AF sensor; and if the distance measurement object has low luminance, the sensor sensitivity is set at high sensitivity, and sensor data is acquired with the entire area of the distance measurement area being the peak selected area, whereby proper sensor data is acquired to carry out distance measurement suitably and reliably.