The utility model is applied to the field of the part and component alignment confirming device, and provides an alignment confirming device of a mask plate, which comprises a positioning tool and a measuring tool. The positioning tool and the measuring tool are movably connected with each other. The utility model can accurately measure whether the position of the mask plate on the operating platform conforms to the design requirements, greatly reduce the quantity of waste products generated due to the deviation of the position of the mask plate, and be widely used in the filed of the mask plate positioning confirmation.