Abstract: A sheet-like heat generation body for use in a microwave oven, which absorbs microwave and generates heat to irradiate food to be cooked. This heat generation body comprises a conductive film, which is made of a crystalline carbon as its principal component, and is formed on a sheet-like base material. The heat-generating body is prepared using a heat-resistant base material and an inorganic bonding agent applied to its surface. Specifically, a heat-resistant base is coated with a mixture of a microwave-absorbing and heat-generating material as its principal component and an agent for hardening an inorganic bonding agent to be applied later. After the mixed agent is dried, it is impregnated with the inorganic bonding agent.