A thermal insulation material contains: a dehydration condensation reaction product of sodium silicate; alumina cement; and smoked charcoal. The thermal insulation material preferably further contains one or more selected from the group consisting of a silica-based hollow balloon, a silicate mineral, and diatomaceous earth. The thermal insulation material has, for example, a board-shaped form. In a method for producing a thermal insulation material, a raw material containing sodium silicate, alumina cement, and smoked charcoal is heated to cause a dehydration condensation reaction of the sodium silicate to occur.