A splitting, a cutting or a cutting-splitting machine with a safety mechanism for limiting access to a splitting knife, wherein the machine has a frame, to which a movable and optionally left-right adjustable conveyor belt is mounted, said conveyor belt being rotatable around a fulcrum in a bottom part of the conveyor belt and has an approximately vertical transport position and a working position at an angle relative to the ground where the machine is located, characterized in that the machine has: - a movable protective plate provided at least on one side of the conveyor belt , the protective plate arranged to cover at least part of the machine frame and part of the conveyor belt side , wherein the protective plate is provided with at least one groove, cut-out, guide or a similar structure , along which a screw, a bolt, a welded or screwed plug with a cotter-pin, a cylinder or a similar element mounted on the side of the conveyor belt and/or on the machine frame, - a connective lever or a handle connected to the protective plate and an axle of the protective plate , which is located in the bottom part of the conveyor belt frame , where said fulcrum is located, wherein the connective lever is on both ends provided with a suitable element arranged to enable rotation in the mounting on the protective plate or a holder or an axle of the protective plate , - the axle of the protective plate mounted in a manner that enables movement of the protective plate together with movement of the conveyor belt due to the connective lever , wherein the connective lever is arranged to move preferably from an approximately horizontal position in a transport position to an approximately vertical position in a working position, wherein the screw, nut, plug or a similar element is arranged to move along the cut-out, groove, guide or any other suitable structure on the protective plate from one extreme position near the machine frame towards the second extreme position at the opposite end of the cut-out, groove, guide or any other structure . - a movable protective plate provided at least on one side of the conveyor belt , the protective plate arranged to cover at least part of the machine frame and part of the conveyor belt side , wherein the protective plate is provided with at least one groove, cut-out, guide or a similar structure , along which a screw, a bolt, a welded or screwed plug with a cotter-pin, a cylinder or a similar element mounted on the side of the conveyor belt and/or on the machine frame, - a connective lever or a handle connected to the protective plate and an axle of the protective plate , which is located in the bottom part of the conveyor belt frame , where said fulcrum is located, wherein the connective lever is on both ends provided with a suitable element arranged to enable rotation in the mounting on the protective plate or a holder or an axle of the protective plate , - the axle of the protective plate mounted in a manner that enables movement of the protective plate together with movement of the conveyor belt due to the connective lever , wherein the connective lever is arranged to move preferably from an approximately horizontal position in a transport position to an approximately vertical position in a working position, wherein the screw, nut, plug or a similar element is arranged to move along the cut-out, groove, guide or any other suitable structure on the protective plate from one extreme position near the machine frame towards the second extreme position at the opposite end of the cut-out, groove, guide or any other structure . <EOS>