Abstract: A thickness measuring device for measuring an object includes a thickness measuring component and a sensing determining means. The thickness measuring component includes a plurality of measuring members provided respectively in correspondence with a plurality of the objects and a holding member. The measuring member is a probe and the holding member includes a plurality of channels. Each measuring member is held by each channel so that each measuring member is operated by the holding member to respectively measure one object by moving itself along an extending direction and/or by irradiating a light to the object. The sensing determining means retrieves an image of the measuring member and/or an image of the light reflected from the object to further obtain and display a thickness value of the object. The thickness measuring device of the present invention is more effective and inexpensive.