Heater and apparatus and method for manufacturing glass product

A heater comprising:

• a heat generating member being conductive and configured to radiate heat rays by being fed with electric power;
• and
• a tubular member composed of a metal and accommodating the heat generating member,
• wherein the heat generating member is composed of a material containing carbon at 80% or more by mass,
• the tubular member is composed of a material including one or more selected from platinum, rhodium, tungsten, iridium, and molybdenum,
• an insulating material is not provided between the heat generating member and the tubular member, and
• the heat generating member is not in contact with the tubular member.