PURPOSE: To enable a highly accurate measurement of a load by arranging at least two of a plurality of pressure-sensitive rings to have the end faces thereof crossing each other at the right angle to eliminate the deformation of a pressure receiving plate.

CONSTITUTION: For example, four pressure-sensitive rings 211W214 are arranged in the form of a box between a substrate 30 and a pressure receiving plate 40 placed parallel with each other and the upper ends thereof are fastened on the pressure receiving plate 40 while the lower ends thereof on the substrate 30. The end faces of the pressure-sensitive rings 211 and 213 are in the direction of crossing those of the pressure-sensitive rings 212 and 214 at the right angle. A strain gage is provided on each of the pressure-sensitive rings 211W214 to detect components of the load.