Semi-automatic electro-pneumatic machine for slicing pressed hams with shank or buffer, bacon, speck or similar products before packing or for trimming products with special shapes; necks, bacons etc. The blades fixed to a rotating head enable the user to alter the cutting format very quickly without having to change them manually in complete safety but simply by automatically rotating the head to the desired cutting position. The sharpness of the blade, combined with a fast and precise downward action, ensures precise cuts of meat. The product is inserted manually outside the processing area, automatically transferred and positioned in the center of the cutting area. When this stage is complete, it is automatically ejected to the side in total safety, thereby avoiding even the slightest contact with the blades. A range of accessories makes this machine functional and easy to use.