Plural heat-exchanging plates for forming an
evaporator have plural projection ribs. The projection ribs protrude toward outside of each pair of the heat-exchanging plates to form therein
refrigerant passages through which
refrigerant flows, and to form an air passage between adjacent pairs of the heat-exchanging plates. The projection ribs protrude from flat surfaces of the heat-exchanging plates toward the air passage to disturb a straight flow of air. The projection ribs are provided in each of the heat-exchanging plates to have a protrusion
pitch (P1) between adjacent two, and the protrusion
pitch is set in a range of 2-20 mm. Further, each of the heat-exchanging plates has a thickness of in a range of 0.1-0.35 mm, and a passage
pitch (P2) between the
refrigerant passages is in a range of 1.4-3.9 mm. Thus, in the
evaporator formed by only using the plural heat-exchanging plates, a sufficient heat-exchanging performance can be obtained.