To reduce an increase in pushing-in force against an operation button in a structure of front-assembling operation button, reduce impact on pushing-in force caused by size variation of button spring, and improve workability when assembling the operation button on a panel.

An operation button structure includes: a panel 1 having an opening 11; a leg part 45 assembled by engaging with the opening 11 at one end, and the other end thereof extending to a switch 2 disposed on a base plate 3 in the panel 1; an operation button 4 for pressing the switch 2 by rotating the leg part 45 around the engaging part at one end as a fulcrum when pushed toward the base plate 3; a button spring 43 provided at one end of the operation button 4, actuated by contacting with an internal wall 15 of the opening 11 with the operation button 4 being pushed in, and giving a restoring force to return the operation button 4 to a position before pushed in; an elastic deformation part 19 which elastically deforms along with the button spring 43 when the operation button 4 is pushed in.