To provide an apparatus for measuring the quantity of electric power consumption capable of displaying the quantity of electric power consumption by an electric apparatus without having to hardly use electric power supplied from an electric power company and enabling a user to freely alter its mounting location.

The apparatus for measuring the quantity of electric power consumption comprises both a power cord clamp part 1 and a main body case 2. The power cord clamp part 1 comprises a plurality of rod-like coils 4 in which a tubular cavity is arranged inside and which are arranged perpendicularly to the cavity. The main body case 2 comprises both an electronic circuit inside and a display 3 at its side surface. A power cord of the electric apparatus is sandwiched between the power cord clamp part 1 to convert electromagnetic noise emitted from the power cord into an electric power supply of the measuring apparatus. By measuring the difference between currents generated in the coils surrounding the power cord, the purpose is achieved.