Electron-irradiation induced amorphization in silicon carbide (SiC) has been investigated using transmission electron microscopy (TEM) equipped with a field-emission gun. Single crystals of 6H-SiC were irradiated with 300 keV electrons at room temperature. Electron diffraction and high-resolution TEM observations indicate that the electron-irradiated area is successfully amorphized. The present irradiation conditions are beyond those required to induce a crystal-to-amorphous phase transformation reported previously (the incident electron energy of >750 keV and the temperature of <290 K). This is attributed to the domination of damage-producing rate over the recovery rate in the electron-irradiated area due to the high electron flux associated with a field-emission gun used in this work.