To provide an inexpensive pipe mounting device which does not need a sealing member between a panel and a connector and has a simple structure having a small number of parts and can be provisionally fixed to the panel with ease and can connect pipes on both sides of the panel.

This device has a plurality of connectors 1 to which pipes are connected at both ends, a connector holder 2 which has a plurality of shaft holes for holding the plurality of connectors 1 therein and is made of elastomer or thermoplastic elastomer and a mounting member 3 for mounting and fixing the connector holder 2 to the opening of a floor panel B. This device is integrally provided with a cylindrical guide wall part 25 into which the connector holder 2 is inserted and is integrally provided with a projection for provisionally engaging the peripheral part of the opening to the outer periphery of the guide wall part 25.