NOVELTY - The biogas plant comprises a digester (301) with specially projected pockets to fix inlet and outlet pipes, a gasholder (302) that concentrically slides over a guide pipe (211), foundation blocks, an inlet chamber (306), and an outlet chamber (307). The inlet and outlet chambers are connected to projected pockets through the inlet and outlet pipes. The guide pipe is rigidly fixed to the foundation blocks. A digester wall has projected pockets with inlet and outlet pipe connections of predetermined length, and connects the digester to the inlet and outlet chambers without any bends.    USE - Used as a ready to install biogas plant.    ADVANTAGE - The ready to install biogas plant can be economically manufactured with high quality and less space and weight, is rapid to install. The digester has inlet and outlet connections without bends thus avoiding chances of blockage and easily cleaning the digester.    DETAILED DESCRIPTION - The ready to install biogas plant comprises a digester (301) with specially projected pockets to fix inlet and outlet pipes, a gasholder (302) that concentrically slides over a guide pipe (211), foundation blocks, inlet and outlet chambers (306, 307) that are connected to the projected pockets through the inlet and outlet pipes. A guide pipe is rigidly fixed to the foundation blocks. A digester wall has projected pockets with inlet and outlet pipe connections of predetermined length, and connects the digester to the inlet and outlet chambers without any bends. The digester, gasholder and inlet and outlet chambers are manufactured in plastics, fiber reinforced plastic, composites, precast concrete and sheet metal. The guide pipe is installed in a center of the digester tank by connecting the guide pipe to the foundation blocks or locking the guide pipe in suitably designed slots in the foundation blocks. Some of foundation blocks have built in a partition wall or provision of slots to install the partition wall. The foundation blocks are fixed to each other and to the guide pipe by an external support such as bolting, riveting and welding or with self locking male female joints.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a biogas plant.    Guide pipe (211)    Digester (301)    Gasholder (302)    Inlet chamber (306)    Outlet chamber. (307)