To improve the efficiency and performance of an object equipment to be controlled by the shortening of a tact time by shortening the operation start time of the object equipment.

This motion controller performs a motion control process MC1 at the start of the motion of the object equipment to be controlled as a periodic scanning process in start timer interruption for every specific fixed-time scan cycle t1 while the motion of the object equipment to be controlled is stopping. When a start command signal for a new motion instruction is inputted at specific time TI, a timer is reset in the input timing TI of this motion start instruction and gets ready to accept a start command, and a motion control process MC2 is started and carried out. After the motion control process is started, a motion control process MC3 at the time of operation is performed as a periodic scanning period for every fixed-time scanning cycle t1.