A shot pump including a cylinder standing upright and an inlet having a check valve which allows a paste-like transferred substance to only flow into the cylinder therethrough. The shot pump also includes an outlet having a check valve which allows the transferred substance to only flow out of the cylinder therethrough. Additionally, a piston is configured to vertically reciprocate in the cylinder, causing the transferred substance to be sucked from the inlet and then to be discharged from the outlet. The ratio of a clearance between a side face of the piston and an inner side face of the cylinder to an outside diameter of the piston is 1/50 to ½. The transferred substance is sucked from the inlet, is then caused to pass through the clearance between the side face of the piston and the inner side face of the cylinder, and is discharged from the outlet.