PURPOSE: To dispense with a guide roller and surely guide a wheel for running along a rail material with simple constitution by forming a guide groove on a part near the inside or the outside of the outer circumference of the wheel for running, and providing a projecting member to guide the guide groove on the upper face of the flange part of the rail material.

CONSTITUTION: A wheel for running 2 is provided on the underside of the bogie main body of a running bogie runningly guided on the upper face of the flange part 1a of a rail material 1 of H-shape steel or the like through a supporting shaft body 3, and a guide groove 4 is formed extending along the whole circumference of the outer circumferential face near the inside of the wheel 2. A line material for guide (projecting member) 5 is arranged on the upper face of the flange part 1a of the rail material 1 loading and supporting the wheel 2 so as to enable to fit in the guide groove 4. As a result, the wheel 2 is surely guided on the decided place on the upper face of the flange part by means of the projecting member provided on the upper face of the rail material through the guide groove.