An image forming apparatus receives setting of an object to be adjusted, on an adjustment object selection screen when selecting an adjustment mode. After the object to be adjusted is set, camera(s) photograph(s) the object to be adjusted so that the image forming apparatus obtains photographed data of current object to be adjusted. Next, the apparatus searches photographed data of the object to be adjusted in the ideal state thereof from the database. Name of the object to be adjusted and related information in the photographed data agree with those of the photographed data of current object to be adjusted. The higher ranked related information is preferentially searched and it is determined whether or not pieces of the higher ranked related information thus preferentially searched agree with each other.