PURPOSE: To provide a column a step difference of which is within a tolerance by forming a counterbore part and a female screw on an end surface of a lengthy cylindrical member and connecting by fitting the counterbore part on a flange part with a connecting member on an intermediate part of which the flange part is formed and on both ends of which male screws are formed.

CONSTITUTION: A fixed member column 10 of a linear motor is constituted as a lengthy cylindrical member is connected by a connecting member 200. A flange part is provided on an intermediate part of the connecting member 200, and male screws are formed on its both end parts. A counterbore part 210 is provided on an end surface of a lengthy cylinder part and female screws are also formed, and fitting the counterbore part on the flange part and are screwed in them. The counterbore part, the female screw parts, the flange part and the male screw parts are respectively machined so as to have required concentricity, and consequently, a step difference of a column circumferential surface is devised to be within an allowable value. Accordingly, the column within a desired dimensional allowable value is provided.