A heat exchanger plate for an evaporator includes a flow transverse distribution device. Disks of the flow transverse distribution device conduct the medium to be evaporated to the flow channel extending in the direction of the longitudinal axis. The disks include openings allowing a flow of the medium in the direction of the longitudinal axis with comparatively higher flow resistance than in the direction of the transverse axis. The number of disks arranged one behind the other in the direction of the longitudinal axis varies over the width of the heat exchanger plate in the direction of the transverse axis. On each width section, in which the entry of the medium into the disks arranged one behind the other is intended, the comparatively largest number of disks is provided one behind the other. As the distance from the entrance increases, the number decreases in the direction of the transverse axis.