1. A function setting device comprising: a first operator that is operated for selecting one function item from among a plurality of function items forming a first menu and for setting the selected function item and for then selecting one function value from among a plurality of function values of the set function item forming a second menu and for setting the selected function value, the second menu being provided for each function item; and a second operator, to which one function item is assigned, that sets the selection of the assigned function item when the second operator is operated for the first time and that selects one function value from among a plurality of function values of the set function item forming the second menu every time the second operator is operated for a subsequent time.