The present invention is characterized in that an apparatus for bone fixation that is composed of a plate and screws fixing the plate to a bone, includes: screws that has a head portion having a male thread on the outer circumference while increasing in diameter toward the upper portion in a tapered shape washers of which the outer circumference is formed convex, and which has, on the inner circumference, a slope that contact with the head portion such that the head portion of the screw is placed and a female thread that is engaged with the male thread of the head portion and a plate that has locking holes which are bored concave in the up-down direction and have a holding step, where the washer is placed, on the inner circumference, in which when the washer and the head of which the female thread and the male thread are partially engaged are inserted from above the locking hole and placed on the holding step, as the head portion is moved down by thread-fastening, the washer is in close contact and fixed in the locking hole while the diameter of the upper end increases. The apparatus for bone fixation according to the present invention has the effect of inserting and fixing the screw perpendicular to the plate because the washer and screw are combined in advance and then fixed to the plate, and allowing an operator to more freely perform an operation because the operator can insert and fix the screw at a desired angle.La présente invention concerne un appareil de fixation osseuse composé d’une plaque et de vis fixant la plaque à un os, l’appareil comprenant : des vis dont chacune comporte une partie de tête dotée d’un filetage mâle sur sa circonférence extérieure tout en augmentant de diamètre en direction de la partie supérieure sous une forme conique une rondelle dont la circonférence extérieure est formée de façon convexe et qui présente, sur la circonférence intérieure, une pente en contact avec la partie de tête de telle sorte que la partie de tête de la vis so
