SUMMARYThree micrographs made at different tilting angles are necessary to determine the spatial coordinates of each point from the surface of micro‐object. The x′ and y′ coordinates of the points are measured in an arbitrary coordinate system O'X′Y′ which ensures convenience in measurements. The coordinates measured are transformed into a main coordinate system OXYZ related to the microscope and the image plane. The z coordinates are calculated. The coordinates of the points are used to solve the following metric problems by applying analytical geometry: computation of (1) distances (between: two points, a point and a straight line, a point and a plane), (2) angles (between: two straight lines, a straight line and a plane, two planes), (3) area of a triangle and (4) volume of a body, which may devided into tetrahedra. A computer program for solving the above problems is written