The invention concerns a flat package for a non sterile protective pouch (16) receiving a sterile surgical mesh; the package includes: an external envelope (2) including a front panel (3) and a complementary back panel (4), the inner face of the front panel (3) and the inner face of the back panel (4) being bonded respectively with a front layer (17) and with a back layer (18) of an internal envelope (15) made of a moisture-impervious material, the front panel (3) and the back panel (4) being jointed along the contours of the external envelope and, the package having an opening end comprising two tearable portions (8) configured to separate the front panel (3) upon which the front layer (17) of the internal envelope (15) is bonded from the back panel (4) upon which the back layer (18) of the internal envelope (15) is attached.