The purpose of the present invention is to provide a joining material that can easily join materials to be joined even when characteristics and physical properties thereof differ greatly. To solve the above problem, the joining material according to the present invention is characterized by including a base material, a first layer that is disposed on one surface of the base material, and a second layer that is disposed on the other surface of the base material and includes a phase having a different coefficient of thermal expansion to that of the phase configuring the first layer, at least one of the first and second layers including glass having a softening point of 600° C. or lower.