PURPOSE: To obtain a load displacement application device which applies a constant load or displacement to plural positions of a structure automatically at the same timing by setting the load or displacement to be applied to the structure previously, detecting the difference between the load or displacement quantity and a set quantity and generating an excess or deficiency signal, and feeding it back.

CONSTITUTION: When a test body 10 is loaded or displaced, an adjustment is so made by a setter 33 previously so that detected quantities of load cells 16A, 17A, 16B, and 17B and displacement gauges 19A and 10B and 0; and a desired load quantity or deformation quantity is determined next, set by the setter 33, and displayed on a display part 32. For example, when a deficiency signal indicating that the load quantity is deficient is sent from a setting display device 30 to a pressure applying device 40, a start button 31 provided to the setting display device 30 is operated. The solenoid valve on the pressure application side of the piping of the pressure applying device 40 is open to send pressurized oil to hydraulic jacks 13A and 13B or 14A and 14B to increase the load. Consequently, the constant load or displacement is applied to plural positions of the structure automatically at the same timing.