A retractable universal safety scalpel comprising a handle having a proximal section and a distal section with a longitudinally extending bore defining a housing； a blade carrier element having mid-section, proximal end and a distal end on which is secured a blade slidably mounted within said housing being capable of getting exposed from the end of distal section of said housing； first and second slilder elements secured to said blade carrier element through a recess formed in the said handle extending from the forward end closer to the said opening to the rear end closer to the distal section of the said handle in a slidable arrangement with the said housing and extending externally in an axial direction of said housing to move said blade carrier moving the said blade from an un-exposed pre-use position to an exposed in-use position and to an after-use position capable of covering and locking permanently the said blade member completely within the said housing of the said handle； a plurality of locking means is provided in the said housing to enable locking of the blade in an un-exposed pre-use position to an exposed in-use position and to an after-use position capable of covering and locking permanently the said blade member wherein the said housing being provided with lock cooperating mechanisms at three positions thereon corresponding to pre-use, in-use and post-use disposal stages, said lock cooperating mechanisms cooperating with the respective locking means provided thereon.L'invention concerne un scalpel de sécurité universel rétractable comprenant un manche possédant une partie proximale et une partie distale comportant un alésage s'étendant longitudinalement délimitant un corps； un élément porte-lame possédant une partie médiane, une extrémité proximale et une extrémité distale sur laquelle est fixée une lame montée coulissante à l'intérieur dudit corps apte à être exposée depuis l'extrémité de la partie distale dudit corps； des premier et second éléments
