PURPOSE: To improve the operational efficiency and shorten the customer's waiting time by a method wherein the printing of fixed data is started by an oil feed starting signal and the printing of variable data is started by a oil feed ending signal.

CONSTITUTION: When a start switch of an operating part 11 is depressed, an oil feed starting signal is supplied from a control device 10 to a control means 17 of a slip issuing device 15 in order to activate a dot printer 14 to print the fixed data such as slip name and trade name and the printer is then held on stanby. At the same time, a starting signal is generated by the control device 10 to drive a motor 3 so as to start oil feed. At that time, the pulse generated by a pulse generator 12 connected to a flow meter 6 is computed by the control device 10 and the oil feed amounts are successively integrated and displayed on an indicating device 13 and an indicating part 16 of the slip issuing device 15. The oil feed is completed and when a stop switch of the operating part 11 is depressed, an oil feed ending signal is supplied from the control device 10 to the control means 17. At the same time, the dot printer 14 prints the variable data such as oil feed amount and unit price in addition to the previously printed fixed data and the printing is completed in a short time.