To provide a fixing structure for an electronic circuit board capable of holding the electronic circuit board without rattle and at a low manufacturing cost.

The structure comprises protrusions 10 formed on both ends in the length direction of a pair of sidewalls 1a and 1a of a case 1 made of a metal material having springness, and cut and raised pieces 20. The protrusion 10 is formed by so cutting and raising a lower end as to tilt toward the inside of the metal case 1, while supporting an upper end. The lower end is formed with a recess 10a that opens toward the inside of the metal case 1. The cut and raised piece 20 is formed as a semicircular cut and raised piece which is bent toward the central side of the sidewall 1a at both ends in the length direction of the sidewalls 1a and 1a closer to an end than the protrusion piece 10. It is so bent as to abut against the side end in the length direction of an electronic circuit board 2 orthogonal to the sidewall of the metal case 1 after the electronic circuit board 2 is engaged with the recess 10a of the protrusion piece.