Provided is a pipe fitting, which is capable of preventing unintended release of a connection between pipes due to an external manipulation and is capable of releasing the connection between the pipes when necessary. This pipe fitting has a housing, a first retainer, and a second retainer. The first retainer has first elastic pieces as well as being slidably disposed inside the housing and being configured so that when the first retainer is located on the connecting section side of the housing, the first elastic pieces are expandable and when the first retainer is located on the inserting section side of the housing, expansion of the first elastic pieces is restricted. An operating pipe section, which can be held at the connecting section end only through an opening in the connecting section of the housing is provided on the second retainer.