Disclosed herein are a trench substrate and a method of manufacturing the same. The trench substrate includes a base substrate, an insulating layer formed on one side or both sides of the base substrate and including trenches formed in a circuit region and a dummy region positioned at a peripheral edge of the trench substrate, and a circuit layer formed in the trenches of the circuit region through a plating process and including a circuit pattern and vias. Thanks to formation of the trenches in the dummy region and the cutting region, deviation in thickness of a plating layer formed on the insulating layer in a plating process is improved upon.