Provided is a bonded body including a ceramic plate; a metal matrix composite (MMC) plate facing one side of the ceramic plate and made of an MMC comprising (i) Si, C, and Ti, or (ii) Al, Si, and C; and a bonding layer interposed between the ceramic plate and the MMC plate and bonding the ceramic plate and the MMC plate to each other, wherein the bonding layer comprises Al as a main component. The MMC plate includes an Al-rich layer in which Al is distributed at a higher concentration than in other regions of the MMC plate over a predetermined depth DAl from a bonding interface between the bonding layer and the MMC plate, and the depth DAl of the Al-rich layer is 40 μm or more.