To provide a heat exchanger 1 with a refrigerant tube 3 being bent in a continuously meandering manner, wherein deterioration of the effective amount of fluid outside tube passing through between plate fins 2 is prevented, and the heat exchanging capacity thereof is secured.

The heat exchanger 1 includes a sealing piece 7, which is arranged in a long hole shaped through-hole 6 formed in a first end plate 4 and a second end plate 5, for blocking the central space of the through-hole 6. While the refrigerant tube 3 penetrating to the through-hole 6, most of the penetrating area of the through-hole 6 is sealed by bending and deforming the sealing piece 7 and blocking the central space of the through-hole 6 so that the fluid outside tube which is supplied to the heat exchanger 1 can efficiently flow between the plate fins 2. Thereby, the amount of the fluid outside tube used for the heat exchanger is secured and the deterioration of the heat exchanging capacity is prevented.