An object is to provide a gas container and a method of producing the gas container in which liner constituting members can appropriately be joined to each other and productivity can be improved. A gas container has a resin liner constituted by joining a plurality of liner constituting members, the liner constituting members each having at least a hollow cylindrical part, and a reinforcement layer arranged on an outer periphery of the resin liner. Joining portions of the liner constituting members are joined to each other over a circumferential direction by laser welding, and the joining portions are made of a laser transmitting resin and a laser absorbing resin, respectively.