An X-ray stress measurement apparatus having: a camera for producing an optical image of a sample; a display for displaying the optical image; an input device capable of inputting positions on a display screen; an X-ray source for generating an X-ray; a table for moving the sample; an X-ray detector for detecting an X-ray exiting the sample; a measurement program for determining the measurement positions of the sample on the basis of the positions indicated by the input device, and measuring the determined measurement positions of the sample; a stress computation program for computing the stress at the measurement positions of the sample on the basis of an output signal from the X-ray detector; and an image formation program for causing the optical image, the measurement positions of the sample, the absolute value of the stress, and the direction of the stress to be displayed on the same display screen.