PURPOSE: A molded article of polyethylene for heat retention having improved heat exchange ability and heat retention ability, obtained by covering polyethylene with an organic silane modified polyethylene to give a compounded molded article, followed by crosslinking the covering layer of the compounded molded article.

CONSTITUTION: A molded article of polyethylene for heat retention with only its surface layer covered with a crosslinked polyethylene obained by covering polyethylene with an organic silane modified polyethylene to give a compounded molded article, followed by crosslinking the covering layer (consisting of the organic silane modified polyethylene) of the compounded molded article. A high- density polyethylene is preferable as the polyethylene, and the organic silane modified polyethylene is a polyethylene obtained by copolymerizing or grafting an ethylenic unsatruated silane compound containing a hydrolyzable organic group (vinyltrimethoxysilane, etc.) onto polyethylene. The crosslinking of the covered layer is carried out sufficiently by allowing it to stand in a normal- temperature atmosphere, and when it is needed to be completed in a short time, it is preferably allowed to stand in a high-temperature constant temperature chamber.