A commodity sales data processing apparatus including a display unit configured to display various kinds of information includes an angle-of-field setting unit configured to set an angle of field of a display screen of the display unit to a first angle of field or a second angle of field narrower than the first angle of field. An angle-of-field control section of the commodity sales data processing apparatus causes the angle-of-field setting unit to operate according to a state of use of the commodity sales data processing apparatus and set the angle of field of the display screen of the display unit to the first angle of field or the second angle of field.