To provide a motor controller, a document scanning device, and a motor control method wherein when acceleration is started when a motor is at a stop, erroneous detection due to chattering can be prevented.

The motor controller includes: a detecting means 80, 100 that detects an edge between high level and low level in an output signal outputted according to the rotation of a motor 50 supplying driving force for transporting an object 30 to be transported and thereby detects the amount of rotation of the motor 50; a determining means 100 that determines whether or not the amount of rotation detected by the detecting means 100 has reached a preset specified amount of rotation for normal rotation; an open controlling means 100 that carries out open control on the motor when the amount of rotation has not reached the specified amount of rotation for normal rotation; and a feedback controlling means 100 that carries out feedback control on the motor 50 when the amount of rotation has reached the specified amount of rotation for normal rotation.