A first header collecting pipe is divided into an upper space corresponding to an upper heat exchange region and a lower space corresponding to a lower heat exchange region. The lower space is divided into a plurality of communication spaces corresponding respectively to auxiliary heat exchange parts of the lower heat exchange region. A second header collecting pipe is divided into a communication space corresponding to both of a first main heat exchange part and the third auxiliary heat exchange part, and into communication spaces corresponding respectively to other main heat exchange parts and the other auxiliary heat exchange parts. Each of pairs of communication space and communication space is connected to an associated one of communication pipes.