To provide a detecting and measuring device for engine load as an important element for the fuel feed control for the lower environmental pollution and lower fuel consumption of an automotive engine or for the power supply control of a hybrid car.

In this load detector for automotive engine, a main movable plate fixed to an engine output main spindle is concentrically connected to a transmission plate fixed to a power transmitting shaft through a measuring spring in such a manner as to be rotatable and slidable, and the expansion and contraction numerical value of the measuring spring caused by the magnitude of a load is measured by approaching and separating a permanent magnet at the tip of a detecting rod to a generation coil by the operation of a can plate and the detecting rod, generating electricity in the generation coil by the circular movement of the magnet, and measuring the intensity of the generated current by use of the law of changing the intensity of the generated current in proportion to the distance between the magnet and the coil, whereby the detection and measurement of the load can be performed. The mechanical numerical value of the load applied to the measuring spring is converted to the intensity of the current, whereby the detection and measurement of positive and negative loads is facilitated.