An image measuring apparatus for enhancing an accuracy of an image captured by an optical system and a method thereof are disclosed. The apparatus includes a CCD camera for capturing the object and outputting the captured image, a lamp for generating white light to illuminate a capturing area of the object, an illumination controller for controlling the lamp to be turned on, a piezoelectric actuator for controlling a minute height of the optical system with respect to the object, an image capturing device for acquiring the image captured by the CCD camera, a driving signal generator for outputting a driving signal to the illumination controller and the piezoelectric actuator when an enable signal is generated from the CCD camera, and an image signal processor for estimating height information of the object from data transmitted from the image capturing unit.