PROBLEM TO BE SOLVED: To provide a method of manufacturing a slidable elastic body made from vulcanized rubber or thermoplastic elastomer, the slidable elastic body being achieved without using an expensive self-lubricating resin, to have an excellent slidability and a durability against repeated slides and maintain a sealability.SOLUTION: A method of manufacturing a slidable elastic body is a method in which a slidable elastic body is made from vulcanized rubber or thermoplastic elastomer as the object to be modified, and the method includes: step 1 in which polymerization initiation points are formed in the modification object by adsorbing polymerization initiator onto the modification object step 2 in which polymer chains are grown on a surface of the modification object by irradiating monomers with light of wavelength in a range of 300 to 400 nm, starting from the polymerization initiation points, then to cause radical polymerization and step 3 in which a fluorine-based oil is adsorbed on surfaces of the polymer chains.
