A new Inertial Electrostatic Confinement (IEC) fusion device has been manufactured as a compact neutron source. This device consists of double jacket chambers to provide sufficient water cooling, having the diameters of inner and outer chambers of, respectively, 20 cm and 30 cm. The effective water-cooling enabled the IEC device to operate at high cathode current of more than 80 mA. A target neutron yield of 1 × 107 has been achieved for cathode voltage of 80 kV and (cathode) current of 80 mA. The water jacket of a 5 cm width was designed as well to assure the sufficient reflection of 2.45 MeV D-D neutrons downward, where a thinner 1 cm thick water jacket is installed at the bottom. This non-uniformity of water jacket thickness resulted in increased neutron flux downward.