A lens apparatus includes a zoom, a focus, a zoom position control signal generator, a focus position control signal generator, a first calculator for calculating a present angle of field from zoom and focus positions, a second calculator for calculating a second angle of field based on a zoom control signal and a focus position, a third calculator for calculating a third angle of field based on zoom and focus position control signals, used when the second calculation unit calculates, a base angle-of-field determinater for determining a sum of the present angle of field and a value obtained by subtracting the third angle of field from the second angle of field, as a base angle of field, and a zoom position control determinater for determining a zoom position to a position of the zoom lens corresponding to the base angle of field to which the zoom lens is driven.