An apparatus has been developed to measure the friction coefficient between the die and the casting at the time of ejection in die casting. The measurement was achieved by measuring the force when a test plate was pulled perpendicularly after the aluminum alloy was shot under high pressure condition. The effects of injection condition, hardness of castings, state of die surface, and spraying condition of lubricants have been discussed and examined. The friction coefficient was very high (1.0-2.0) in the case of non-lubrication, and it decreased as hardness of castings increased and roughness of die surfaces decreased. The friction coefficient decreased and then became constant (0.2-0.3) with increasing in the amount of layers of lubricants.