Abstract: A position detecting method is disclosed wherein the position of an object is detected by the use of pattern information which are taken from an observational region on the object contained within a whole region. Positional information of at least one of standard pattern is extracted from a pattern of the whole region are stored in advance; positional information of the standard pattern are extracted from the pattern taken from the observational region on the object; and the positional information of the standard pattern in the whole region and the observational region are compared, to decide which part of the whole region the observational region is and to detect the position of the object.