Disclosed is an ozone-generating unit wherein the ozone-generating unit, to which a control means that has a plurality of means for outputting ozone gas, is miniaturized. Further disclosed is the obtaining of the abovementioned ozone-generating unit. Furthermore, a gas ductwork collecting block (30) has a plurality of internal ductwork paths (R30a-R30f), and by means of this plurality of internal ductwork paths, an ozone generator (1), a control means (MFC(3), gas filter (51), and APC (4)), a starting-gas supply port (14), an ozone gas output port (15), and a coolant inlet/outlet (13A, 13B) being connected, a starting-gas input ductwork path from the starting-gas supply port to the ozone gas generator with the APC therebetween, and an ozone gas output ductwork path from the ozone generator to the ozone gas output port with the gas filter, an ozone concentration meter (5), and the MFC (3); therewbetween, can be formed as an integrated unit.