To provide a receiving seat used when installing an article outside a pipe by using a bolt.

The bolt 5 is penetrated in the radial direction of the pipe 6 from holes arranged in two places of the pipe 6, and the bolt 5 projecting outside the pipe 6 is inserted into this receiving seat 1. A fastening member having a female screw part is threadedly engaged with the bolt 5 inserted into the receiving seat 1. A leg part 3 is pressed to and tightly contacted with an outer peripheral surface of the pipe 6 by fastening the bolt 5, and the bolt 5 is fixed to the pipe 6. Clearance is arranged between a receiving seat body 2 and the pipe 6, and the receiving seat can be applied to a pipe different in an outer diameter.