An image scanner is provided and includes a case having a document placement surface, two carriages which are mounted with optical components and move by running on rails, a wire drive mechanism for reciprocating the two carriages which are coupled to wires, and a movement restricting member for restricting a maximum movement distance of the first carriage in a stationary position mode to about 1.6 d or less, d being a groove depth of pulleys in mm and the maximum movement distance being a distance by which the first carriage is allowed to move in the read scanning direction in the stationary position mode in which the first carriage is kept stopped and fixed via the wires by moving the second carriage by causing the wire drive mechanism to operate so that the second carriage hits the fixedly disposed member to be stopped and fixed.