NOVELTY - The integrated multi-measurement system comprises a thickness gage (3) for measuring a change in thickness of a gas diffusion layer sample depending on the applied pressure of a motor (2) and a rod (11). Upper plated sheet (5) comes into contact with the lower portion of the descending plate to press gas diffusion layer sample. The upper plated sheet has gas outlets for discharging gas via internal passage. A control box (1) includes a differential pressure gage for measuring differential pressure for the in-plane and through-plane of gas diffusion layer sample being pressed by motor and rod.    USE - Integrated multi-measurement system for physical properties such as thickness, electrical resistance and differential pressure of gas diffusion layer of polymer electrolyte fuel cell with respect to compression, for use in design and manufacture of fuel cell stack.    ADVANTAGE - Measures physical properties while simultaneously measuring the changes in the physical properties depending on the clamping pressure. Temperature of the integrated multi-measurement system is controlled in order to measure differential pressure of the gas diffusion layer depending on relative humidity. Based on accurate values of the physical properties, the clamping conditions of the fuel cell can be optimized, and two-phase flow in the gas diffusion layer can be understood. Can ascertain the effect of bypass flow into the gas diffusion layer onto performance of the fuel cell, thus allowing to design and manufacture a separator for uniform gas distribution. Attains measurement system having a high industrial applicability.    DETAILED DESCRIPTION - A lower plated sheet (4) is located under the upper plated sheet. A milliohm meter wire is connected to milliohmeter connection terminals (71,72) mounted respectively at upper and lower plated sheets for measuring electrical resistance.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic diagram of the integrated multi-measurement system.    Control box (1)    Motor (2)    Thickness gage (3)    Lower plated sheet (4)    Upper plated sheet (5)    Rod (11)    Milliohmeter connection terminals (71,72)