A focus adjusting apparatus that is connected to a camera that images a moving object at predetermined time intervals, the focus adjusting apparatus comprising: an acquiring unit configured to acquire a first image and a second image from the camera, the first image having a first portion corresponding to the moving object at a first position, the second image having a second portion which is lower than the first portion and is corresponding to the moving object at a second position nearer to the camera than the first position; a calculating unit configured to calculate a first out-of-focus level of the first portion within the first image, and to calculate a second out-of-focus level of the second portion within the second image; and a focus adjusting unit configured to determine whether both the first out-of-focus level and the second out-of-focus level are smaller than a predetermined value, adjust the focus of the camera onto a position shifted in a direction away from the camera when either one of the first out-of-focus level and the second out-of-focus level is larger than the predetermined value and the first out-of-focus level is larger than the second out-of-focus level, and adjust the focus of the camera onto a position shifted in a direction toward the camera when either one of the first out-of-focus level and the second out-of-focus level is larger than the predetermined value and the second out-of-focus level is larger than the first out-of-focus level. an acquiring unit configured to acquire a first image and a second image from the camera, the first image having a first portion corresponding to the moving object at a first position, the second image having a second portion which is lower than the first portion and is corresponding to the moving object at a second position nearer to the camera than the first position; a calculating unit configured to calculate a first out-of-focus level of the first portion within the first image, and to calculate a second out-of-focus level of the second portion within the second image; and a focus adjusting unit configured to determine whether both the first out-of-focus level and the second out-of-focus level are smaller than a predetermined value, adjust the focus of the camera onto a position shifted in a direction away from the camera when either one of the first out-of-focus level and the second out-of-focus level is larger than the predetermined value and the first out-of-focus level is larger than the second out-of-focus level, and adjust the focus of the camera onto a position shifted in a direction toward the camera when either one of the first out-of-focus level and the second out-of-focus level is larger than the predetermined value and the second out-of-focus level is larger than the first out-of-focus level. determine whether both the first out-of-focus level and the second out-of-focus level are smaller than a predetermined value, adjust the focus of the camera onto a position shifted in a direction away from the camera when either one of the first out-of-focus level and the second out-of-focus level is larger than the predetermined value and the first out-of-focus level is larger than the second out-of-focus level, and adjust the focus of the camera onto a position shifted in a direction toward the camera when either one of the first out-of-focus level and the second out-of-focus level is larger than the predetermined value and the second out-of-focus level is larger than the first out-of-focus level.