To improve the supporting strength of an upper arm in a support leg of a desk or the like.

The rear part of the upper arm 8 is fitted between an opening part 93 provided in the upper end of a front plate part 91 in a leg panel 9 and both outside plate parts, inward engagement pieces 94 provided in the upper ends of the both outside plate parts 92 in the leg panel 9 are made to abut on the rear part upper face 83a of the upper arm 8, and an abutment part 11a provided at the upper arm 8 and projecting outward from its outer face abutting on the circumferential edge of the opening part 93.