To provide an extendable leg and a table apparatus having the same, which eliminate troublesome mechanical processing of the extendable leg by incorporating a guide unit freely raised.

A pair of extendable legs 2 and 2 are composed so that second leg rods 7 are freely extended with respect to first leg rods 6 through raising guide units 16. Two pairs of the raising guide unit 16 are incorporated on two inner walls of the first leg rod 6, and the raising guide unit 16 is composed of an external sash bar 17 longitudinally disposed in the first leg rod 6 and an internal assembly 18 rising and moving along the external sash bar 17, fixed to the upper part of the second leg rod 7, and longitudinally disposed along the second leg rod 7. The external sash bar 17 has a long rod shape, and is attached with a retainer 20 processed into a semi-arcuate cross section at both longitudinal edges and holding a number of rollers 19 therein. The internal sash bar 18 abuts on the rollers 19 of the retainer 20 between both longitudinal edges in the external sash bar 17 in the width direction of the external sash bar 17, and is movably engaged along the external sash bar 17.