To provide a work base having a structure capable of folding a ladder frame down freely, allowing a worker to carry and move it easily by himself if either of the opposing ladder frames is folded down as well as in a condition in which they are folded down, and having ease-of-use.

This work base is constituted in such a way that a plurality of step muntins 2 are attached between a pair of support column legs 1 having an extended handrail support column 4 in an upper part at an adequate interval to form the ladder frame 3, a pair of ladder frames 3 are opposed, and their upper ends are mutually and turnably fixed, a tread unit 6 is stretched between the ladder frames 3 at an upper part position of the support column leg 1 so as to fold it freely, the support column leg 1 is composed of divided bodies of an upper part main leg 1a and a lower part main leg 1b, and a lower end of the upper part main leg 1a and an upper end of the lower part main leg 1b are mutually and turnably connected by a connection fitting 10 to combine the upper part main leg 1a with the lower part main leg 1b in parallel so as to fold them down freely. A castor 29 is attached to an inner side in a lower part on at least one side of the opposing ladder frames 3.