The invention relates to a medical device including a base member and a coating layer containing an antithrombogenic material and covering a surface of the base member. The antithrombogenic material contains a copolymer having a repeating unit (A) represented by the following formula (1) : wherein R 11 is a hydrogen atom or a methyl group, Z is an oxygen atom or -NH-, R 12 is a C 1-6 alkylene group, R 13 and R 14 are each independently a C 1-4 alkyl group, and R 15 is a C 1-2 alkylene group, and a repeating unit (B) represented by the following formula (2): wherein R 21 is a hydrogen atom or a methyl group, R 22 is a C 1-6 alkylene group, and R 23 is a C 1-4 alkyl group. The repeating unit (A) is contained in a proportion of 1 to 7 mol% based on all the structural units of the copolymer. The invention makes it possible to provide a medical device having excellent antithrombogenicity even under severe use conditions prone to thrombus formation.
