Semi-automatic electro-pneumatic machine for slicing various types of cold meats such as ham, coppa, bacon, mortadella, speck, etc. before packing or for trimming products into special shapes such as neck, pancetta cubes, etc. The blades are fixed to a rotating head which quickly alters the cutting format without the need to change it manually. This simple, safe operation is done automatically by rotating the head to the desired cutting position. The sharpness of the blades, combined with a fast and precise downward action of the top blade, ensures extremely precise cuts of meat. A range of accessories makes this machine functional and easy to use. Inserting and removing the product is done manually. Where required, the machine can be supplied with an automatic device for positioning the product in the centre so as to have equal-size slices and/or to eject the product automatically.