An isotope separator was constructed and operated with on-line connection to the INS FM cyclotron. The gas-discharge type ion source was used in the earlier stage. Later the ion source was improved to the hollow-cathode type in order to achieve high temperature and high efficiency. The mean radius and the deflection angle of the separator are 60 cm and 45°, respectively. Mass-separated ions are transported through concrete walls to a tape collector, where radioactivities are measured. As a test experiment, natural copper foils were bombarded with the 52 MeV proton beam, and the reaction products of ⁶³Zn, ⁶²Zn, ⁶¹Zn and ⁶⁰Zn were separated. The delay time between production and measurement was shortened to 1 min for the Zn isotopes evaporated from the 10 μm Cu foil. Yield ratios of ⁶¹Zn to ⁶³Zn were measured for proton energies of 30–47 MeV.