To provide a laying or carrying device using air pressure capable of preventing air leakage and noise caused by air leakage, freely setting a slit position and applying itself even to a complicated curved route.

This laying or carrying device using air pressure constituted of a slit pipe 1 on which a slit 2 is formed, a slit seal member 3 to seal the slit 2 and an inner moving body 4 to move along an inner peripheral surface 5 of the slit pipe 1 and constituted to transmit movement of the inner moving body 4 by pneumatic pressure to the outside has characteristics that the aforementioned slit 2 is furnished with a storage part 22 to store and hold the slit seal member 3, the aforementioned slit seal member 3 is furnished with a seal member main body 31 to be stored in the aforementioned storage part 22 and a protruded part 32 to fit in the slit 2, and sealing of the slit 2 by the slit seal member 3 is carried out by making an edge part 25 provided on the slit 2 contact with an edge contact flat surface 35 provided on the slit seal member 3.