PURPOSE: To obtain a counter capable of measuring AC electric energy consumed in a load.

CONSTITUTION: This counter comprises a circuit of outputting two measured voltages in proportion to a voltage applied to a load and strength of a current flowing in the load, respectively, and a circuit of outputting a voltage signal representing an algebrasical product of two measured voltages. The latter circuit comprises an A-D transducer 14 for changing a measured voltage Ur of a voltage applied to a load to a digital signal, analog digital mixture amplifiers 18, 20 for inputting this digital signal and a voltage Ui representing strength of a current and supplying an output voltage Up in proportion to the algebraical product, and a voltage and frequency transducer 24 for generating an output pulse representing a quantum specifying power consumption.