PURPOSE: To easily perform the measurement of the tensile strength of a fragile material by using a standard tensile tester, by adhering a tough auxiliary member to the parts essentially mounted to a tester at both ends of a specimen by using an adhesive and transmitting load to the specimen through said member.

CONSTITUTION: A specimen 1 is a fragile material and metal round rods 2, 3 are tough auxiliary members and adhered to both ends of the specimen 1 by using an adhesive. The upper end of the metal round rod 2 is processed so as to have a diameter slightly smaller than the inner diameter of the lower end of the specimen 1 and adhered in a state sufficiently deeply inserted in the specimen 1 and a shuckle 5 is mounted to the lower end of said rod 2 through a pin 4. The lower end of the metal round rod 3 is processed so as to have a diameter slightly smaller than the inner diameter of the upper end of the specimen 1 and adhered in a state of being sufficiently deeply inserted in the specimen 1 and the upper end of said rod 3 is fixedly clamped by a chuck 7 having a grip face 6 in order to make the fixing of the rod 3 certain. In performing a tensile test, a base stand 9 is mounted to one tensile force applying part of a tensile tester and a universal joint 8 is mounted to the other tensile force applying part and the tensile tester is operated in a usual way.