PURPOSE: To downsize a device and facilitate the working.

CONSTITUTION: This device has a vertically extending hole 1 formed in the center, and a plurality of grooves 2 radially formed on both upper and lower surfaces with the hole 1 as center. The thin part nipped by the grooves 2 on both the upper and lower surfaces is formed into a distorting generating part 3 which is distorted when a load is added, and a strain gauge 4 is mounted on at least either one of both the surfaces of the distorting part 3. The thick part between the distorting parts 3 is alternately formed into a pressure receiving part 5 and a grounding part 6, and the upper and lower surfaces of the pressure receiving part 5 is formed higher than the upper and lower surfaces of the grounding part 6, and the load added to the pressure receiving part 5 is electrically amplified and detected as a distortion in the position of each distorting part 3, and displayed.