In object detection method and apparatus, a detection image related to a binary image obtained by subtracting a background image from an input image delivered from an image-pickup device is displayed on the display screen of a display unit, responsive to an operation done by an operator who determines that at least one object in the displayed detection image is a region to be excluded from object detection, the region of the object is set as a masking region automatically and thereafter, object detection is performed in respect of individual input images while performing masking in the masking region.