The purpose of the present invention is to provide a medical material capable of suppressing adhesion of platelets and proteins even when in contact with biological components such as blood for an extended period of time. The present invention provides a medical material that is a copolymer comprising hydrophobic units and hydrophilic units in which the hydrophobic units have a C2-20 terminal alkyl group in a side chain, the static contact angle of water in the copolymer is at least 30 degrees and less than 70 degrees, and the glass transition temperature of the copolymer exists at only one point in the range from 45 DEG C to less than 90 DEG C.本發明係以提供一種即使長時間與血液等生物體成分接觸也能抑制血小板或蛋白質的附著的醫療用材料為目的。本發明係提供一種醫療用材料，其為包含疏水性單元與親水性單元的共聚物，上述疏水性單元係於側鏈具有碳數2~20的末端烷基，上述共聚物之水的靜態接觸角為30度以上且小於70度，上述共聚物的玻璃轉移溫度係於45℃以上且小於90℃的範圍僅存在一點。
