PURPOSE: To provide a display method of each work indicating slip that calls forth an operator, whose attention has become vague due to a continuation of the same work, to pay attention to an alteration of job contents and makes any misoperation preventable, in the work indicating slip attached at every work in a manual line where various works for assembling multispecified products are mixedly flowing as in an automotive engine manufacturing line.

CONSTITUTION: An indicating part different from and adjacent work is made to be printed by a printer for printing out two work indicating slip 5a, 5b as a turnover display part 6. Black-and-white turnover characters are printed on this turnover display part 6, thereby calling upon an operator to pay attention to the print and preventing any misoperation from occurring.