Provided is a novel infusion set that includes a first member which configures a main tube and a second member which configures a side tube. This infusion set enables priming to be performed with a simple step without leakage of a liquid by placing a cap having: an opening that allows gas inside the cap to pass therethrough but does not allow a fluid or a solid to pass therethrough by providing a hydrophobic filter at a site deeper inside the cap than a distal end of a connector for connecting to a three-way branch valve or a connector for connecting an infusion needle that is inserted inside the cap from an insertion opening and a lid provided outside the opening for closing the opening . This infusion set is optionally colored, and improves workability by enabling the first and second members to be optionally connected with the three-way branch valve 5. Thus, with this infusion set for which a standard use process can be easily determined, stability of the infusion set and an IV stand is maintained, leakage at the site where an infusion needle is inserted and physical pain of patients are prevented, and occurrence of accidents caused by human error in the administration process is prevented.
