To provide a load sensor which can inexpensively, arbitrary, and easily set its operating low-output voltage level when the sensor is used for the operating section of game equipment or the bonding device, etc., of a personal computer.

A load sensor is constituted by fixing a substrate 1 which is made of an elastic insulating resin and on which two pairs of first and second strain detecting elements 5 and 6 are arranged and a reinforcing plate 2 made of an elastic metal to a mounting base 4 in a state where the substrate 1 and plate 2 are put upon another. Therefore, such a load sensor that can inexpensively and easily set an arbitrary operating load-output voltage by timely selecting the material, shape, thickness, etc., of the reinforcing plate 2 against the operating load of a prescribed operating shaft 3 can be obtained.