In an evaporator, each fin is disposed between adjacent tubes in a tube stacking direction, and each of the tubes includes at least first and second tube parts lined to have a space therebetween in a flow direction of air passing between the adjacent tubes. The first tube part has therein a first refrigerant passage that is completely separately from a second refrigerant passage of the second tube part. Furthermore, the fin has at least one open portion that is opened from an end of the fin in the tube stacking direction to a predetermined portion, and the open portion is provided in the fin except for a position in the air flow direction, corresponding to the space. Therefore, the strength of the evaporator can be increased while condensed water on the evaporator can be effectively drained.