A leaf spring load measuring device of the present invention comprises a weighing mechanism, a measuring mechanism, a metering mechanism, and a control mechanism. The weighing mechanism applies a load heavier than a working load to a leaf spring, thereby bending the leaf spring in its thickness direction, and maintains the resulting state for a predetermined hold time. The measuring mechanism measures a load value of the leaf spring in a manner such that the spring is subjected to a load within a range of the working load. The metering mechanism meters a displacement of the spring when the load value is measured. The control mechanism controls the weighing mechanism, the metering mechanism, and the measuring mechanism, and has a timer function to meter the hold time.