A single glass panel for a fire door and a double glazed glass panel for a fire door that have a fireproofness with which the glass sheet passes an international standard ISO 0834 flame insulating performance test and are as inexpensive as possible. For example, the single glass panel for a fire door is obtained by forming a heat reflecting coating with a low emissivity on at least one surface of a glass sheet that is a heat strengthened glass sheet or is more thermally strengthened than a heat strengthened glass sheet, and the double glazed glass panel for a fire door includes a first glass sheet (2B) obtained by forming a heat reflecting coating (4) with an emissivity of 0.07 or less on at least one surface of a glass sheet that is a heat strengthened glass sheet or is more thermally strengthened than a heat strengthened glass sheet and a second glass sheet (2C) that is a heat strengthened glass sheet or is a glass sheet more thermally strengthened than a heat strengthened glass sheet, the first glass sheet (2B) and the second glass sheet (2C) being arranged to face each other with a gap therebetween such that at least one layer of said heat reflecting coating (4) is placed between the two glass sheets (2B) and (2C).