An operation device, characterized by: an operation inputter (311, 381) configured to operate a robot, the robot comprising a leading end and a multi-articular arm configured to change a position and a posture of the leading end; a screen outputter configured to output, to the operation inputter (311, 381), at least one operation image on which a motion command for the leading end of the robot is input; a calibrator configured to, based on an input into the operation inputter (311, 381), perform a calibration of setting a posture of a second coordinate system, associated to the operation inputter, relative to a first coordinate system, associated to the robot for controlling the robot, at a preset initial posture; a device posture detector (321, 382) configured to detect a posture of the operation inputter (311, 381) in the first coordinate system; a coordinate system turner configured to, based on the posture of the operation inputter (311, 381), turn the second coordinate system, the second coordinate system being turnable relative to the first coordinate system; a command generator configured to, upon execution of a point operation of specifying at least one point on the operation image: determine a motion direction of the leading end of the robot in the second coordinate system such that the motion direction is correlated with a positional relationship between the one point and a reference point on the operation image; determine a motion scalar quantity of the leading end of the robot such that the motion scalar quantity is correlated with a distance between the one point and the reference point; and generate the motion command such that the motion command comprises the motion direction and the motion scalar quantity; a command convertor configured to convert the motion command into a first-coordinate-system motion command for the leading end of the robot in the first coordinate system; and a command outputter configured to output a control command for controlling the robot based on the first-coordinate-system motion command. an operation inputter (311, 381) configured to operate a robot, the robot comprising a leading end and a multi-articular arm configured to change a position and a posture of the leading end; a screen outputter configured to output, to the operation inputter (311, 381), at least one operation image on which a motion command for the leading end of the robot is input; a calibrator configured to, based on an input into the operation inputter (311, 381), perform a calibration of setting a posture of a second coordinate system, associated to the operation inputter, relative to a first coordinate system, associated to the robot for controlling the robot, at a preset initial posture; a device posture detector (321, 382) configured to detect a posture of the operation inputter (311, 381) in the first coordinate system; a coordinate system turner configured to, based on the posture of the operation inputter (311, 381), turn the second coordinate system, the second coordinate system being turnable relative to the first coordinate system; a command generator configured to, upon execution of a point operation of specifying at least one point on the operation image: determine a motion direction of the leading end of the robot in the second coordinate system such that the motion direction is correlated with a positional relationship between the one point and a reference point on the operation image; determine a motion scalar quantity of the leading end of the robot such that the motion scalar quantity is correlated with a distance between the one point and the reference point; and generate the motion command such that the motion command comprises the motion direction and the motion scalar quantity; a command convertor configured to convert the motion command into a first-coordinate-system motion command for the leading end of the robot in the first coordinate system; and a command outputter configured to output a control command for controlling the robot based on the first-coordinate-system motion command. determine a motion direction of the leading end of the robot in the second coordinate system such that the motion direction is correlated with a positional relationship between the one point and a reference point on the operation image; determine a motion scalar quantity of the leading end of the robot such that the motion scalar quantity is correlated with a distance between the one point and the reference point; and generate the motion command such that the motion command comprises the motion direction and the motion scalar quantity; a command convertor configured to convert the motion command into a first-coordinate-system motion command for the leading end of the robot in the first coordinate system; and a command outputter configured to output a control command for controlling the robot based on the first-coordinate-system motion command.