PROBLEM TO BE SOLVED: To provide a vertical port passage forming device which forms a digging groove at a vertical port passage forming position by scooping soil of a farm field and discharging the same to the side by using a lower part of a plow member as a traveling machine body advances, allows a penetration mark groove and a vertical port passage to be opened in the digging groove to suppresses the same from being blocked by mud on the field surface, and makes water on the field surface reach a core soil layer located in the underground from the openings of the penetration mark groove and the vertical port passage through the digging groove, thereby a distance from the ground surface of the farm field to the core soil layer is reduced, and accordingly, drainability and air-permeability of the farm field can be favorably maintained.SOLUTION: Provided is a vertical port passage forming device for a farm field, which is formed by providing on a machine frame 3, a plow member 27 capable of forming a digging g
