A specified position in an array structure in which a reference pattern is displayed repetitively through reference pattern counting is identified. In an array structure image, the pattern detection estimating area generated from a starting point, the address of the starting point, and a unit vector are compared with a pattern detected position found in pattern matching with the reference pattern image, to execute pattern counting while determining correct detection, oversights, wrong detection, etc. Array structure images are photographed sequentially while moving the visual field with the use of an image shifting deflector to continue the pattern counting started at the starting point to identify the ending point specified with an address. If the ending point is not reached only with use of the image shifting deflector, the visual field moving range of the image shifting deflector is moved with use of a specimen stage.