A crawler traveling apparatus includes a rubber crawler belt having a plurality of driving projections formed with a predetermined peripheral pitch on an inner peripheral face of the belt, a drive wheel rotatable when engaged with the driving projections of the crawler belt for driving the belt, and a plurality of free wheels rotatable for laterally guiding the driving projections under movement. Each driving projection has an upper half having a lateral face including an upper half lateral face portion and a lower half having a lower half lateral face portion, the upper half lateral face portion having an erect inclination angle smaller than an erect inclination angle of the lower half lateral face portion. Each free wheel has an inner lateral face opposed to the driving projection, the inner lateral face having an inclined guide face having an inclination parallel to the lower half lateral face portion of the driving projection. The inclined guide face has a height L3 shorter than a height L1 of the lower half lateral face portion when an inner peripheral face of the crawler belt is placed under proper contact with an outer peripheral face of the free wheel.