Abstract: The present patent discloses an electric grinder, comprising a shell, a motor assembly, a grinding assembly and a dust cover. The motor assembly and grinding assembly are provided in the shell, and an opening is provided at one end of said shell. The dust cover comprises a cover and a counterweight part, and can open or close the opening of the shell under the gravity of the counterweight part. In the electric grinder provided by the present invention, when the opening of the grinder faces downward, the dust cover can open automatically. When the opening of the grinder faces upward, rotating the dust cover can close and engage with the opening of the dust cover automatically. Thus, the present invention prevents the feed opening of the electric grinder from being exposed to air when the user forgets to close the dust cover.