A robot controller controls an arm tip end portion of a robot to move at constant predetermined speed on the basis of a movement path including an arc portion, the robot controller including: a centrifugal force calculation unit that calculates a centrifugal force acting on the arm tip end portion as time series data; a transformation unit that performs Fourier transformation with respect to the time series data of the centrifugal force into frequency data; and a speed determination unit that determines the predetermined speed such that a frequency component in a predetermined range including a natural vibration frequency of the robot is equal to or less than a threshold on the basis of frequency data of the centrifugal force.