To provide an electric vacuum cleaner with excellent handleability by displaying the amount of dust with only two wires inside an extension pipe.

In this electric vacuum cleaner, when the large amount of dust is passed inside an infrared sensor 13, a microprocessor 17 lights a first LED 24 by a first photo triac coupler 18. When the small amount of the dust is passed inside the infrared sensor 13, the microprocessor 17 lights the first LED 24 at low luminance by performing the thinning control of the first photo triac coupler 18. Thus, since a user easily visibly confirms the amount of the dust and sets appropriate suction force, usability is extremely improved.