2 10 8The invention addresses the problem of providing a medical material and a hemoperfusion machine of high anti thrombotic properties and safety. The machine is obtained by incorporating a medical material wherein: a hydrophilic copolymer is present on the surface contacting the blood 3/µm or less of particulate protuberances of 50 nm or higher particle diameter are present on said blood contacting surface and the relaxation time at 40°C of water adsorbed to the hydrophilic copolymer is 5.0 x 10 seconds to 2.5 x 10 seconds.
