residual and mesh
 

Hi,
how can I see which node has the highest residual, which is shown in *.out file?

Typically the out file reports the highest residual over ALL timesteps, with the highest residuals typically occuring in the first few timesteps, so it's fairly useless info. Instead, in Pre under Output Control > Results ask to write the residual fields to the res file, then you can plot them in Post like any other variable.