A thermal insulating material which can be efficiently produced while the content of organic matters, such as organic fibers and/or an organic binder, is reduced to the same or lower degree as compared with the thermal insulating material used in a conventional pollution control device (e.g., catalytic converter), and which can be applied to a pollution control element (e.g., catalytic element) while avoiding, as much as possible, an unpleasant feeling to the operator. A thermal insulating material comprising a thermal insulating material body formed of a bulk material of inorganic fibers, and a coating provided on at least one surface of said thermal insulating material body.