An image reader capable of entering a power save mode for saving power consumption during standby includes: a gain amplifier; a reference white plate that is to be scanned when gain control of the gain amplifier is performed to obtain a controlled gain value; a carriage that moves to an stops at an area corresponding to the reference white plate when the image reader enters the power save mode; a gain storage section that stores the controlled gain value as a recovery parameter when the image reader enters the power save mode; and a gain setting section that sets the recovery parameter as the controlled gain value when the image reader exits the power save mode.