To prevent a single pole table, whose top plate is made elevated by a gas spring, from being rotated by a simple and inexpensive means.

An upward facing fixed tube 11 equipped on the upper face of a support leg 2 and a downward facing movable tube 28 are fit together slidable in the vertical direction, and at the same time, a lateral guide groove 30 is equipped on either one of the inward and outward facing faces of the fixed tube 11 or the movable tube 28 and an engaging protrusion 21 to slidably fit in the guide groove 30 on the other, and a gas spring 13 whose piston rod is made extensible in the vertical direction against the main body 14 is installed so that either of the main body 14 or the piston rod 15 is fixed on the support leg 2 and the top plate 23 is supported by the other.