The machine for grinding sheet-like elements, particularly tiles and slabs made of ceramic material, natural stone, glass or the like, includes a base framework, means for advancing at least one sheet-like element on a movement plane (A) along an advancement direction (B), the sheet-like element being provided with a pair of opposite first sides to be ground and a front side transversal to the first sides and defining the advancement front of the sheet-like element, means for machining the first sides adapted to intercept the sheet-like element in the motion thereof along the advancement direction (B), means for square-positioning the sheet-like element on the movement plane (A) comprising at least one abutment element which defines at least two support points adapted to contact the front side for arranging it in a position orthogonal to the advancement direction (B).