Isolation device (1; 50; 100; 150; 200) for absorbing seismic waves suffered by a reference surface comprising: - a lower plate (2; 51; 101; 151; 201) suitable to be firmly constrained through anchoring means to a reference surface; - an upper plate (4; 52; 102; 152; 202), separated from said lower plate (2; 51; 101; 151; 201) and suitable to support at least one object to be isolated and/or protected; - linear guide means (5; 103; 153), interposed between said lower plate (2; 51; 101; 151; 201) and said upper plate (4; 52; 102; 152; 202) which are firmly coupled with, suitable to make said upper plate (4; 52; 102; 152; 202), when a seismic wave acts on said reference surface, sliding with respect to said lower plate (2; 51; 101; 151; 201) along two longitudinal directions (X, Y) orthogonal each other from an initial position, in which said upper plate (4; 52; 102; 152; 202) is vertically aligned with respect to said lower plate (2; 51; 101; 151; 201), to a plurality of temporary positions, in which said upper plate (4; 52; 102; 152; 202) is vertically decentralized with respect to said lower plate (2; 51; 101; 151; 201); - absorbing means of said seismic wave, interposed between said lower plate (2; 51; 101; 151; 201) and said upper plate (4; 52; 102; 152; 202) and operatively connected with said upper plate (4; 52; 102; 152; 202), suitable to impart a resistance force against sliding of said plate upper (4; 52; 102; 152; 202) along said longitudinal directions (X, Y) in order to dissipate the energy generated by said seismic wave on said reference surface; - elastic re-centering means, interposed between said lower plate (2; 51; 101; 151; 201) and said upper plate (4; 52; 102; 152; 202) and operatively connected with said upper plate (4; 52; 102; 152; 202), suitable to bring said upper plate (4; 52; 102; 152; 202) back from any of said temporary positions to said initial position after said seismic wave has been occurred on said reference surface, characterized in that said absorbing means of said seismic wave and said elastic re-centering means are grouped in a same elastically yielding element (8; 57; 154; 207) made of non-linear elastic deformation material and present in one or more exemplars. - a lower plate (2; 51; 101; 151; 201) suitable to be firmly constrained through anchoring means to a reference surface; - an upper plate (4; 52; 102; 152; 202), separated from said lower plate (2; 51; 101; 151; 201) and suitable to support at least one object to be isolated and/or protected; - linear guide means (5; 103; 153), interposed between said lower plate (2; 51; 101; 151; 201) and said upper plate (4; 52; 102; 152; 202) which are firmly coupled with, suitable to make said upper plate (4; 52; 102; 152; 202), when a seismic wave acts on said reference surface, sliding with respect to said lower plate (2; 51; 101; 151; 201) along two longitudinal directions (X, Y) orthogonal each other from an initial position, in which said upper plate (4; 52; 102; 152; 202) is vertically aligned with respect to said lower plate (2; 51; 101; 151; 201), to a plurality of temporary positions, in which said upper plate (4; 52; 102; 152; 202) is vertically decentralized with respect to said lower plate (2; 51; 101; 151; 201); - absorbing means of said seismic wave, interposed between said lower plate (2; 51; 101; 151; 201) and said upper plate (4; 52; 102; 152; 202) and operatively connected with said upper plate (4; 52; 102; 152; 202), suitable to impart a resistance force against sliding of said plate upper (4; 52; 102; 152; 202) along said longitudinal directions (X, Y) in order to dissipate the energy generated by said seismic wave on said reference surface; - elastic re-centering means, interposed between said lower plate (2; 51; 101; 151; 201) and said upper plate (4; 52; 102; 152; 202) and operatively connected with said upper plate (4; 52; 102; 152; 202), suitable to bring said upper plate (4; 52; 102; 152; 202) back from any of said temporary positions to said initial position after said seismic wave has been occurred on said reference surface,