PURPOSE: To obtain a chimney model being stood on a topographical model in which the delivery port of tracer gas is held invariably even if the topographical model is turned and the tracer gas is delivered surely in the horizontal direction.

CONSTITUTION: The turnable chimney model being stood on a topographical model turnable about a vertical axis in a wind tunnel and delivering a tracer gas horizontally through a delivery port provided at the forward end thereof comprises a connection pipe 2 turnable about the vertical axis while being supported by the topographical model, an L-type pipe 5 communicating with the connection pipe through a flexible tube 3 with a tracer gas delivery port 1 being provided at the forward end thereof, and a supporting member 4 for securing the connection pipe 2 and the L-type pipe 5 such that the delivery port 1 at the forward end thereof lies on the vertical rotary axis of the topographical model.