A technology for placing spacers free from the occurrence of streaks is provided. Random numbers are generated by a computer, and made in one-by-one association with discharge positions of an object for discharging every generation, and stored in a memory unit of the computer. Coefficient values are determined for the respective discharge positions based on the stored random numbers, and individual voltage values to be required for the respective discharge positions are calculated through the multiplication of voltages set for respective nozzle holes N1 to Nn by the coefficient values. When the respective voltages corresponding to the discharge positions are applied to piezoelectric elements inside a discharge head and a discharge liquid containing the spacers are discharged through the plural nozzles N1 to Nn provided in the discharge head, the spacers are placed on the object for discharging by numbers according to the random numbers.