A device for protecting an injection apparatus for injecting a product, the said apparatus comprising a needle and a piston connected to an actuating rod surmounted by a piston head, the said device comprising: a support sleeve, a protective sleeve for protecting the needle, first retaining means for holding the protective sleeve in its standby configuration in a first position, second retaining means for holding the protective sleeve in its standby configuration in a second position, an intermediate collar comprising collaboration means for collaborating with the piston head, and deactivation means for deactivating the first and second retaining means. The second retaining means being able to be deactivated by the deactivation means of the intermediate collar by the release of the pressure of the piston head on the collaboration means of the intermediate collar to allow the protective sleeve to deploy under the action of pushing means.