Heat exchanger and refrigeration cycle device

A heat exchanger of the embodiment has a first header, a second header, a plurality of heat exchanging tubes, and refrigerant piping. The first header and the second header are disposed in parallel with a space therebetween. The heat exchanging tubes are arranged in the header extension direction, the direction in which the first header and the second header extend, with spaces therebetween and connect the first header and the second header. The refrigerant piping is connected to one header and supplies refrigerant into the one header. The refrigerant piping has a supplying unit. The supplyingunit generates, in the refrigerant supplied to a communication space, a velocity component in the header extension direction and a velocity component in the direction toward the heat exchanging tube 实施方式的热交换器具有第封头和第二封头、多个热交换管以及制冷剂配管。第封头和第二封头相互隔开间隔地并列设置。热交换管在第封头和第二封头所延伸的封头延伸方向上隔开间隔地排列，并且连接第封头和第二封头之间。制冷剂配管连接于方的封头，向方的封头内供给制冷剂。制冷剂配管具有供给部。供给部使供给到连通空间的制冷剂生成沿着封头延伸方向的速度成分以及沿着朝向热交换管的方向的速度成分。