<p>Small operation device and operation system, which can easily be arranged in a limited space such as an instrument panel of a vehicle are provided. A mode change-over switch (10) for switching a mode of an operation object and a dial switch (20) for setting the respective modes are disposed in the same axis. A spring member (40) is fixed to a linking part (22) of the dial switch (20).The linking part (22) of the dial switch (20) is inserted into a clicking number update member (60) having a cylindrical part (61) and a spindle part (64). The spindle part (64) is inserted into a guide groove formed in the cylindrical part (12) of the mode change-over switch (10). The clicking number update member (60) is moved to an axial direction by turn of the mode change-over switch (10). Two clicking faces where recess parts or projecting parts whose number differs in a circumferential direction are formed are arranged in the axial direction on an inner peripheral face of the cylindrical part (61) of the clicking number update member (60). One clicking face is engaged with the spring member (40) by shift of the clicking number update member (60) in the axial direction.</p>
