PURPOSE: To simply and accurately set a measurement stroke, and continuously change the stroke while thrust is being measured by mounting a movable stand in such a way that both a position detecting sensor and a thrust detecting sensor can be interlocked in the axial direction.

CONSTITUTION: A stationary block 3 and a thrust detecting sensor (load cell) 4 are disposed in a form that they are integrated or are in contact with each other, a movable stand 6 is moved to the reference position (for example, a termination position) of a solenoid stroke with a handle 7 operated, the output of a position detecting sensor (digital gauge) 5 is made a reference position, and simultaneously the position of the recording pen of a XY recorder is also set at a reference position. After the movable stand 7 has been moved to a starting point with the handle 7 operated, let measurement current flow to the solenoid, the generated thrust of the solenoid is detected by the cell 4 so as to be inputted into the XY recorder, and simultaneously the position of the cell 4 is detected by the gauge 5 so as to be inputted to the other side of the XY recorder. By this constitution, thrust stroke characteristics can thereby be measured simply and continuously at a great number of stroke positions.