PURPOSE: To dispense with bolts, washers and bolt holders of a device for fixing a bush cutting blade and to actualize miniaturization, light weight and reduction in cost.

CONSTITUTION: The lower part of a bush cutting blade shaft 55 is engaged with an upper holder 59, the bush cutting blade shaft is screwed with a male screw 57 formed at the bottom of the bush cutting blade shaft 55 and a lower holder 61 for sandwiching a bush cutting blade shaft 43 between the upper holder 59 and the lower holder and fixing the bush cutting blade shaft is installed.