PURPOSE: To simply and speedily fold up a bicycle.

CONSTITUTION: A frame body 2 for a folding bicycle has a head pipe 10, a front frame 11, a rear frame 12, a handle lock mechanism 14 and a frame lock mechanism 17. A front fork 4 to support a front wheel 5 is installed in the head pipe 10. In the front frame 11, the tip is connected to the head pipe 10 by a bearing part 13 so as to be rotatable around a vertical shaft. In the rear frame 12, the tip is connected to the front frame 11 by a hinge 16 so as to be rotatable around a vertical shaft, and a rear wheel 6 can be supported with the other end. The handle lock mechanism 14 locks the head pipe 10 and the front frame 11 so as to be freely releasable. The frame lock mechanism 17 locks the front frame 11 and the rear frame 12 so as to be freely releasable.