PROBLEM TO BE SOLVED: To provide a polymer compound capable of inhibiting activation of a coagulation system, a complement system or a blood platelet system when coming in contact with an in-vivo tissue or the blood and a composition and equipment using the polymer compound.SOLUTION: The polymer compound comprises repeating units which are formed by binding side chains containing an ether structure through an ether bond to the principal chain constituting the polymer and contains at least either of repeating units of formula (A) and repeating units of formula (B), where R4Ok is a cyclic ether having a three- to six-membered ring and k is the number of oxygen atoms contained in the cyclic ether and 1 or greater.
