A seal structure includes a first member including a first joint surface and a flat third joint surface; a second member including a second joint surface joined with the first joint surface, a flat fourth joint surface; and a third member including a fifth joint surface joined, through a liquid seal, with the flat third and fourth joint surfaces. At least the second member includes a recessed portion. The fifth joint surface includes a flat region and a chamfered region which is recessed from the flat region and which confronts the recessed portion.