Abstract: In a refrigerant evaporator, plural tubes made of aluminum are arranged in a laminating direction perpendicular to an air flowing direction, and plural corrugated fins made of aluminum are disposed between adjacent tubes. In the evaporator, when a tube plate thickness TT of the tubes is set in a range of 0.10 mm-0.35 mm and a tube height TH of each tube in the laminating direction is set in a range of 1.5 mm-3.0 mm, pressure loss of refrigerant in a refrigerant passage becomes smaller, and a heat-conductive area of air becomes larger. Further, when a fin height FH of the corrugated fins is set in a range of 4.0-7.5 mm, fin effect of the corrugated fins is improved. As a result, heat-conductive performance of the evaporator is improved.