The invention provides a
heat pipe which can improve
backflow efficiency of
working fluid, thereby having excellent
heat transfer characteristics. A
heat pipe (1), in a sealed container (2) having an internal space (S) in which a
working fluid (F) has been sealed, is provided with: an
evaporation unit (3) that evaporates a liquid-phase
working fluid (FL) and changes the phase into a gas-phase working fluid (Fg); a condensation unit (4) which is disposed at a position separated from the
evaporation unit (3) and which condenses the working fluid (Fg) in the
gas phase and changes the phase of the working fluid (Fg) into the working fluid (FL) in the
liquid phase; and an intermediate part 5 located between the
evaporation part 3 and the condensation part 4. The
heat pipe (1), when viewed from the cross-section of the
evaporator (3), has: a first sintered body layer (6) that is formed from a sintered body of a first
copper powder and that is formed in a specific region on the inner
peripheral surface (2a) of the sealed container (2); and a second sintered body layer (7) comprising a sintered body of a second
copper powder having a larger average particle
diameter than that of the first
copper powder and formed in a ring shape over the entire inner
peripheral surface (2a) of the sealed container (2) in a state in which the first sintered body layer (6) is interposed between the second sintered body layer (7) and the inner
peripheral surface (2a) of the sealed container (2).