To provide a chemical vessel capable of completely eliminating liquid type chemical products residual on a main line immediately before completion of unloading.

In this chemical vessel provided with a cargo line for loading and unloading liquid type chemical products between plural tanks installed in a hull and various facilities, the cargo line is provided with plural manifold crossover lines extended along width around a center of the hull, and connected to the facilities at one end, plural first and second main lines connected to the crossover lines at one end, and extended toward the bow and the stern of the hull at a higher level than the crossover line, and plural branch lines connected to at least either the first or the second main line at the other end and in the middle, vertically extended at a main part, and inserted into the tank at a lower end where a submerged pump is installed.