A heat transport device includes an evaporator, a condenser, and a vapor channel and a plurality of liquid channels that connect the evaporator and the condenser. The evaporator generates a capillary force to circulate working fluid. This structure prevents the performance deterioration and malfunction due to the entry of vapor-phase working fluid into the liquid channels. Since the cross-sectional areas of the liquid channels gradually decrease from the condenser toward the evaporator, the capillary force at the liquid channels can be increased, and vapor-phase working fluid is prevented from entering the liquid channels. Wicks and the portions of the liquid channels adjacent thereto are filled with liquid-phase working fluid even after dryout occurs, stable operation is achieved.