A controller controls a plunger to operate at a measurement speed and discharge the viscous material from the nozzle before applying the viscous material to the workpiece. The controller measures a period of time, from when the plunger starts operating at the measurement speed until a discharge amount of the viscous material reaches a predetermined value, as a time delay amount. The controller further determines an operation speed of the plunger and/or a moving speed of the nozzle during application of the viscous material to the workpiece according to the measured time delay amount.