A support device (1) is provided for, comprising a support surface (2) suitable to be placed in contact with an object at least one inflatable device (3), comprising an air chamber (30) suitable to vary its extension depending on the internal pressure thereof, and an inflation valve (31) suitable to permit a variation of the pressure inside the air chamber (30), at least one depressurisation device (4) positioned between the air chamber (30) and the support surface (2) and comprising: - a main casing (40) impermeable to the passage of fluid, flexible and defining a main volume (40a) an inner casing (41) placed inside the main casing (40), permeable to the passage of gas and flexible filler particles (42) housed in the inner casing (41) a depressurisation valve (43) suitable to form or interrupt a connection for fluid passage between the main volume (40) and the environment external to the main volume (40) and suitable to permit the depressurisation of the main volume (40a) defining a relaxed configuration in which the filler particles (42) are movable inside the inner casing (41) and a compressed configuration in which the filler particles (42) are compacted and substantially define at least one solid body (42a).
