Depth measurement apparatus and method

A depth measurement apparatus including an illumination module, a beam splitter, an objective lens, an image capture module, a controller and a processor is provided. The illumination module is configured to generate an illumination beam. The beam splitter and the objective lens are disposed on an optical path of the illumination beam, and the object lens is configured to focus the illumination beam into a hole formed in an object. The image capture module is configured to capture images of the hole at different heights. The controller is coupled to the illumination module and the image capture module. The processor is coupled to the controller and the image capture module, and configured to perform focus distance evaluations on the images captured by the image capture module to obtain a height difference between two surfaces of the object. A depth measurement method is also provided.