An object of the present invention is to provide a pattern measuring apparatus which performs high-accuracy concavity/convexity determination (e.g., distinguishing between a line segment and space) while simultaneously reducing the dose of a beam falling onto a pattern to be measured. To attain the object, this invention proposes a pattern measuring apparatus which specifies a pattern in a measurement object area by scanning a tilted bean with respect to another area different from the measurement object area and then performs measurement based on the pattern-specifying result. With such arrangement, it becomes possible to perform measurement without the risk of wrong pattern designation while lowering the dose of a beam hitting the measurement object area.