To provide an apron structure in which durability of a water sealing material is improved, the water sealing material is brought into press-contact with a periphery of an inspection hole without depending on a locking piece or a screw, thereby a time for attachment/detachment of an inspection hole lid is shortened.

The apron structure includes an inspection hole 41 provided in an apron 4 of a bathtub and an inspection hole lid 42 for closing the inspection hole 41. An apron side projection member 411 projecting to the side of the inspection hole lid 42 is provided on a periphery of the inspection hole 41, and a lid side projection member 423 projecting to the inspection hole 41 side is provided on a periphery of the inspection hole lid 42. The water sealing material 44 for sealing all area in a circumferential direction with respect to the lid side projection member 423 is attached to the apron side projection member 411. The water sealing material 44 is provided with a press-contact part 443 resiliently deformed between both projection members 411 and 423 when the inspection hole 41 is closed with the inspection hole lid 42 to come in press-contact with the lid side projection member 423.