PURPOSE: To obtain an automatic gate cutter in which cutting jigs are attached to a circulating carrying passage and the gates can be continuously cut by means of cutters.

CONSTITUTION: An automatic gate cutter 1 is a device for cutting the gate of a nonferrous alloy casting, and comprises a carrying passage 10 for making rotary-type circulation, a plurality of cutting jigs 20 mounted on the carrying passage 10 and a cutter 30 provided at a prescribed position in contact with the carrying passage 10 for cutting gates protruding from the cutting jigs 20. A cast product exchanging position 40 is provided at a position most separated from the cutter 30 in the carrying passage 10. The cutting jigs 20 are circulated by the carrying passage 10 and the gates of the cast products are cut along the reference planes of the cutting jigs 20 by the cutter 30, so that a cutting operation can be safely and continuously carried out.