An information reading apparatus that is easy for a user to operate even if different functions are required for each situation is provided. A base module includes a control unit which performs control by using three functional modules assembled thereto, that is, a top module, a bottom module, and a back module, and a touch panel whose display content is controlled by the control unit. The top module is connected to a one end of the base module in the longitudinal direction, the bottom module is connected to the other end of the base module in the longitudinal direction, and the back module is connected to a rear side of the base module, which faces away from a display screen of a touch panel. The control unit recognizes each function on the basis of the information obtained from the three functional modules connected to the base module.