INORGANIC PLATE MANUFACTURING METHOD AND INORGANIC PLATE

[Object] An object is to provide an inorganic board and a method for manufacturing the same that are suited to achieving high waterproofness.[Solution] A manufacturing method of the present invention includes first to sixth steps. The first step involves depositing a raw material on a receiving plate B1 to form a first layer L1. The second step involves pressing a first portion Ma and a second portion Mb of a raw material mat M including the first layer L1 toward the receiving plate B1 to compress the first portion Ma and the second portion Mb. The first portion Ma and the second portion Mb are one end portion and the other end portion, respectively, of the raw material mat M in a first direction D1. The third step involves depositing a raw material on the first layer L1 to form a second layer L2. The fourth step involves planarizing an exposed surface of the second layer L2. The fifth step involves curing the raw material mat M pressed between the receiving plate B1 and a pressing plate B2 to form a cured plate M' from raw material mat M. The sixth step involves processing the first portion Ma and the second portion Mb into a first back-side joint part P1 and a first front-side joint part P2, respectively. An inorganic board X1 according to the present invention includes the first back-side joint part P1 and the first front-side joint part P2 that are high-density parts.