A focus-controlling apparatus adjusts a focus in an optical system. The apparatus includes a focus detecting unit, a storage unit, a focus area switching unit, and a drive control unit. The focus detecting unit detects de-focusing amounts of the optical system with respect to a plurality of objects that lie in a plurality of focus areas, respectively. The storage unit stores the de-focusing amounts detected for the respective focus areas. The focus area switching unit switches the focus areas, from one to another, in an order based on the de-focusing amounts stored in the storage unit. The drive control unit moves the optical system to a focus position corresponding to the de-focusing amount at any focus area switched by the focus area switching unit.