A speed controller includes a drive source, an input device for inputting the driving speed information of the drive source, a driver for driving the drive source on the basis of the driving speed information input by the input device, a detector for linearly detecting the amount of movement of the drive source, an output device for outputting movement amount information obtained by the detector, and a corrector for correcting the driving speed information by the use of the movement amount information obtained by the detector, the corretor imparting new driving speed information as the corrected value to the driver.