Retaining holder for fuel injector

The sealing unit (2) for a fuel injection valve (1) in a bore (3) of a cylinder head (4) comprises a main body (15) with an axial bore (16) with an enlarged section (18) which accommodates a sealing element (17). The respective bearing faces of the main body lie at least indirectly against the face of the injection valve and the face of the step in the bore (3). Also claimed is a holding down unit (22) for a fuel injection valve (1). This unit takes the form of an incomplete ring which is joined to a lever arm (24) fixable to the cylinder head by means of a screw. The gap in the ring mates with a housing element of the injection valve, and prevents rotation of the latter.