According to the invention, irrespective of conditions of the variable conductance heat pipe during storage, transportation and installation, the stable actuation and stable operation thereof can be obtained. A variable conductance heat pipe is provided. The variable conductance heat pipe includes a sealed container in which a working fluid and a noncondensable gas are sealed, the sealed container extending in an axial direction. The sealed container includes one end to be connected to a heating source and a part to be connected to a heat sink. On a cross section of the sealed container alonga direction orthogonal to the axial direction, a portion having water conveying property better than other portions is provided. The portion having the better water conveying property extends in the axial direction.