The invention provides a contact pad for measuring electrical thickness of gate dielectric layers and a measurement structure thereof, and belongs to the technical field of semiconductor manufacturing. In the provided contact pad, the area of an underlying pad metal layer in the prior art is reduced by composition to be not larger than the area of a gate electrode; and interlayer pad metal layersare replaced with interconnected metal layers with area smaller than that of a top pad metal layer, thus increasing capacitance gap of parasitic capacitance of the first pad metal layer, and being capable of greatly reducing the parasitic capacitance of the contact pad. Measurement accuracy is high when the measurement structure comprising the contact pad and a contact pad for extracting electrodes from a semiconductor substrate is used for measuring the electrical thickness of gate dielectric layers.