PROBLEM TO BE SOLVED: To easily change a position for the time of non-use and for the time of use with a foot while a foot switch is kept connected to and engaged with a device body.SOLUTION: A support structure of a foot switch includes: a locking part 3 of the foot switch 2 provided on a sidewall part 102 of a device body 101 and an engaging part 23 provided on the front part of the foot switch 2 and capable of being engaged with the locking part 3 freely movably in the vertical direction. When not using the foot switch 2, the gravity of the foot switch 2 acting on a fulcrum part 6 formed below the engaging part 23 and abutted to the sidewall part 102 makes holding force generated between the locking part 3 and the engaging part 23 and between the sidewall part 102 and the fulcrum part 6 act, and the foot switch 2 is locked and held so as not to be abutted to a floor. When using the foot switch 2, the rear part of the foot switch 2 is attached to the floor and supported and the front part of the foot switch 2 is supported by a stopper part 5 provided on the device body 101.
