For the first time, a superconducting RF gun where a photocathode is inside a superconducting cavity has been working stably over a period of seven weeks. The gun with a half-cell cavity has been operated in the cryostat at 4.2 K. A maximal field strength of 22 MV/m in the cavity and maximal beam energy of 900 keV have been obtained. Measurements of beam current, transmission, energy spread and transverse emittance are presented and discussed.
