PURPOSE: To count up the number of pieces of a simple substance rapidly and exactly even if each unit weight is changed by dividing the whole simple substance into plural times when the fixed quantity of the simple substance is supplied and stored in a case or the like, weighing the supplied process sequentially to find out the weight of every divided feeding, subtract the weight value by the average weight of the simple substance and convert the divided value into the number of pieces.

CONSTITUTION: A weight detector 15 can weight the simple substance 1A correctly by using a simple substance carrying device 10 as its tare and the weight of the discharged and placed simple substance 1A is continuously inputted to a counting condition decision control circuit 22 as a weight signal WS through an input circuit 23. The circuit 22 divides the gradually increased weight of the simple substance 1A sequentially by the average weight A and converts the divided value into the number pieces of the simple substances, and when the number pieces of the simple substance on a belt reaches the allowable maximum feeding number M, closes a simple substance feed valve 4. When the weight signal WS from the weight detector 15 is stabilized, te circuit 22 finds out the exact weight value, divides the weight value by the average weight A of the simple substance inputted from the data input device 28 to find out the number N1 of feed pieces.