To provide a mat for an operating table having a body pressure dispersing action and a body pressure dispersing type posture holding device to be used in a medical, welfare and care filed.

This body pressure dispersing mat 10 comprises a body formed of a viscoelastic gel substance G and a film F covering it; and a bottom E formed of an elastomer having hardness higher than the gel viscoelastic body. This body pressure dispersing mat and the posture holding device are formed of the body pressure dispersing body described in the claim 2 wherein the viscoelastic body has a thickness of 5-30 mm and 25% compressive stress of 10-90 kPa; the film has a thickness of 0.05-0.2 mm, its tensile strength of 50-100 MPa, an elongation percentage of 450-800 %, and tear strength of 100-200 N/m; and the elastomer has the thickness of 1-6 mm and JIS-A hardness of 5-50.