The steps of handling ice cans in an ice making plant, such as placing the ice cans in alignment within one or more ice tanks, transferring ice cans each containing formed ice block to a stripping-off area, and placing and separating of the cover lid relative to ice can units, are automatically performed by an overhead travelling crane.Particularly, several ice can units are placed in the ice tank such that pairs of lugs provided on each ice can unit are arrayed in two straight lines to enable the overhead crane to selectively lift the ice cans.In order to produce high-quality ice blocks which are completely transparent through to the core portion thereof, each ice can is correlated with means for agitating ice making water contained therein and is connected with a piping for exchanging core water, in which impurities or foreign particles are likely to gather, with fresh water.The stripping-off of the ice blocks from the ice cans is also performed by an automatic system.