A measuring method for performing monitoring measurement on two or more objects to be measured by a measuring instrument, which comprises a telescope unit for sighting an object to be measured, a distance measuring unit for projecting a distance measuring light through said telescope unit and for measuring a distance to said object to be measured, an image pickup unit for acquiring a digital image by projecting a sighting light and capturing a reflection thereof through said telescope unit, an angle detecting unit (31, 32) for detecting a directional angle in sighting direction of said telescope unit and an automatic sighting unit for carrying out automatic sighting on said object to be measured by said telescope unit, comprising a step of setting up a searching range, a light amount switch-over step of switching over a light amount of projected sighting light to a first light amount for a short distance or a second light amount for a long distance which second light amount is larger than said first light amount for a short distance, a short distance searching step of searching the searching range using the light amount for short distance and of performing a coarse measurement on the objects to be measured as positioned at short distance, a long distance searching step of searching the searching range using the light amount for long distance and performing a coarse measurement on the objects to be measured as positioned at long distance and a precise measurement step of carrying out automatic sighting on all objects to be measured based on the result of coarse measurement of said short distance searching and on the result of coarse measurement of said long distance searching and of distance measurement using the distance measuring unit and angle measurement on each of the objects to be measured, wherein said short distance searching step comprises a scanning step of scanning said searching range through said telescope unit, an image acquiring step of acquiring digital images at a predetermined time interval using said image pickup unit in the process of scanning, a directional angle measuring step of measuring a directional angle at the time of image acquisition using said angle detecting unit, an image position detecting step of detecting an image of the objects to be measured in said digital image and of detecting an image position of the image of the objects to be measured, and a coarse measurement step of measuring a composite directional angle of each of the objects to be measured based on the result of the directional angle measurement and the result of detection of image position, wherein said long distance searching step comprises a scanning step of scanning said searching range through said telescope unit, a digital image acquiring step of acquiring digital image at a predetermined time interval using said image pickup unit in the process of scanning, a directional angle measuring step of measuring a directional angle at the time of image acquisition using said angle detection unit, an image position detecting step of detecting an image of the object to be measured in said digital images, of performing a masking processing of images on the objects to be measured positioned at a short distance based on the result of said coarse measurement as acquired by said short distance searching and detecting an image position of the image of object to be measured positioned at long distance, and a coarse measurement step of measuring a composite directional angle of each of the objects to be measured based on the result of directional angle measurement and the result of the detection of image position.