A manufacturing apparatus of porous glass base material, including a plurality of deposition apparatuses (31A, 31B) that manufacture a porous glass base material by generating raw material particles from vaporized raw material compounds in an oxyhydrogen flame, and then depositing the generated raw material particles on a rotating starting material, the manufacturing apparatus comprises: at least one storage container (2, 12) for storing the raw material compound in liquid form for each compound; at least one vapor generation mechanism (3, 13) for vaporizing the raw material compound in the storage container (2, 12); and at least one gas channel for supplying the raw material compound vaporized by the vapor generation mechanism (3, 13) to the plurality of deposition apparatuses (31A, 31B), wherein the gas channel includes: a common gas channel (4, 14) that is shared to supply vaporized raw material compounds to the plurality of deposition apparatuses (31A, 31B); and a plurality of individual gas channels (104A, 104B, 114A, 114B) that are branched off from the common gas channel (4, 14) to supply vaporized raw material compounds to each of the deposition apparatuses (31A, 31B) individually, and wherein each of the plurality of individual gas channels (104A, 104B, 114A, 114B) includes: a flow controller (103A, 103B, 113A, 113B) that controls the flow rate of the vaporized raw material compound; a steam valve (102A, 102B, 112A, 112B) that controls the on/off of the vaporized raw material compound distribution; and a valve (101A, 101B, 111A, 111B) that is provided upstream from the flow controller and can adjust the flow channel cross-section area. at least one storage container (2, 12) for storing the raw material compound in liquid form for each compound; at least one vapor generation mechanism (3, 13) for vaporizing the raw material compound in the storage container (2, 12); and at least one gas channel for supplying the raw material compound vaporized by the vapor generation mechanism (3, 13) to the plurality of deposition apparatuses (31A, 31B), wherein the gas channel includes: a common gas channel (4, 14) that is shared to supply vaporized raw material compounds to the plurality of deposition apparatuses (31A, 31B); and a plurality of individual gas channels (104A, 104B, 114A, 114B) that are branched off from the common gas channel (4, 14) to supply vaporized raw material compounds to each of the deposition apparatuses (31A, 31B) individually, and a common gas channel (4, 14) that is shared to supply vaporized raw material compounds to the plurality of deposition apparatuses (31A, 31B); and a plurality of individual gas channels (104A, 104B, 114A, 114B) that are branched off from the common gas channel (4, 14) to supply vaporized raw material compounds to each of the deposition apparatuses (31A, 31B) individually, and wherein each of the plurality of individual gas channels (104A, 104B, 114A, 114B) includes: a flow controller (103A, 103B, 113A, 113B) that controls the flow rate of the vaporized raw material compound; a steam valve (102A, 102B, 112A, 112B) that controls the on/off of the vaporized raw material compound distribution; and a valve (101A, 101B, 111A, 111B) that is provided upstream from the flow controller and can adjust the flow channel cross-section area. a flow controller (103A, 103B, 113A, 113B) that controls the flow rate of the vaporized raw material compound; a steam valve (102A, 102B, 112A, 112B) that controls the on/off of the vaporized raw material compound distribution; and a valve (101A, 101B, 111A, 111B) that is provided upstream from the flow controller and can adjust the flow channel cross-section area.