PURPOSE: To correctly compound rubber-compounding chemicals in a predetermined order, by indicating the arranged position of a compounding chemical and checking the taking-out operation of the chemical on te basis of reading by a card reader.

CONSTITUTION: An apparatus comprises a card reader 1, an indicator 10 for indicating the arranged position of each compounding chemical, a sensor for detecting the taking-out operation of the chemical, and an instructor for pointing out either normal or abnormal operation. Chemical boxes 14 necessary for rubber-compounding are arranged at the periphery of a work table 35. When a card expressing the compounding contents is inserted into the card reader 1, the indicating lamp 10 of the chemical box 14 reserving a compounding chemical to be compounded at first is lighted. If an operator correctly opens the cover of the box 14 and takes out the compounding chemical, the lamp 10 is put off. If the operator erroneously opens the cover of a different box, an alarm buzzer attached to the reader 1 gives a warning singnal. The second compounding operation and so on are carried out in the same manner.