A modified fiber and a method for producing the same. The modified fiber is obtained by modifying a fiber material containing at least one of a cellulosic fiber and an animal fiber. In the modified fiber, a film of a silicone elastomer is attached to at least a portion of a surface of the fiber material, the silicone elastomer contains a polyoxyethylene alkyl ether having 12 to 15 carbon atoms as a main component and has a siloxane skeleton, and the surface has a surface tension of 30 to 70 mN/m.