A medical device which comprises a base material and a hydrophilic polymer layer, said hydrophilic polymer layer being provided in at least a part of the base material, and satisfies requirements (a)-(d): (a) the polymer constituting the hydrophilic polymer layer is a hydrophilic polymer containing acidic groups； (b) the thickness of the hydrophilic polymer layer is 1 nm or more and less than 100 nm； (c) the ratio by number of basic groups/acidic groups in the hydrophilic polymer layer is not more than 0.2； and (d)when measured 40 minutes after immersing in a phosphate buffer solution and subjecting to ultrasonic cleaning, the liquid film retention time is 15 seconds or longer. Provided are the medical device, wherein the surface of the base material has been hydrophilized, and a method for manufacturing the same by a simple process.本案發明係提供一種醫療器材，係具有基材、與於上述基材之至少一部分具有親水性聚合物層而成，並滿足下述(a)~(d)之條件：(a)構成上述親水性聚合物層之聚合物為含有酸性基之親水性聚合物；(b)上述親水性聚合物層之厚度為1nm以上且未滿100nm；(c)上述親水性聚合物層之鹼性基/酸性基的數量比為0.2以下；(d)浸漬於磷酸緩衝液並施加超音波洗淨40分鐘後的液膜保持時間為15秒以上。並提供使基材表面經親水化之醫療器材及藉由簡便方法製造其之方法。
