An evaporator includes two heat exchangers including an entry-side heat exchanger and an exit-side heat exchanger which are arranged opposite each other. The entry-side heat exchanger has a first path, a second path, and a third path, and the exit-side heat exchanger has a fourth path, a fifth path, and a sixth path. The sectional area of heat exchange passages of the first path in which refrigerant from an entry firstly flows downward is set smaller than the sectional area of heat exchange passages of the fifth path in which the refrigerant lastly flows downward. The sectional area of heat exchange passages of the sixth path in which the refrigerant to an exit lastly flows upward is set smaller than the sectional area of heat exchange passages of the second path in which the refrigerant firstly flows upward.