To suppress noise occurring when generating a supply power, and to reduce a cost.

In a power supply section 90, a positive voltage +VDD and a negative voltage -VDD with prescribed levels (e.g., +4.2 V and -3.0 V) are generated by using a power from a main power supply. A load cell 20 is supplied with the positive voltage and the negative voltage, and the positive voltage is supplied to an amplifying section 30, an AD converting section 40, an interface section 50, and an arithmetic processing section 60. An electric signal corresponding to a load is outputted by the load cell 20, and the electric signal is amplified by the amplifying section 30, an output of the amplifying section 30 is converted into a digital signal by the AD converting section 40, and the digital signal is processed by the arithmetic processing section 60, thereby providing data indicative of the load.